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No. 36 


WINDMILLS 

AND 

WIND MOTORS 

How to Build and Run Them 


BY 

F. E. POWELL 























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PREFACE 


I have endeavoured in the following pages not 
only to interest the practical amateur in a branch 
of mechanics unfortunately much neglected, but 
also to present a series of practical original de¬ 
signs that should prove useful to every reader 
from the youngest to the most advanced. This 
is admittedly a large undertaking, and would be 
of doubtful wisdom, but for the sparseness of the 
literature of the subject. There is, however, 
no other book in the language, large or small, 
dealing with the matter in the way here pre¬ 
sented, and indeed only one other, as far as I 
know, having the subject of windmills for its 
sole topic. I venture to hope therefore that this 
little book will help to arouse something of the 
interest the subject deserves but has not hitherto 
received. 

That I am right in claiming for the wind 
motor a more serious recognition I am con¬ 
vinced, and particularly is this the case in re¬ 
gard to the model engineer. At present there 
is every prejudice against wind-power on ac¬ 
count of its uncertainty, against which even its 
inexpensiveness has not been able to contend, 
iii 



IV 


PREFACE 


If it can once be realised, however, that the un¬ 
certainty can be reduced to little or no import¬ 
ance, so much that even a petrol-engine might 
seem unreliable and troublesome beside it, the 
claim put forward for the windmill is fully sub¬ 
stantiated. Not less than this is one of the aims 
of this little book, and it is one which I confi¬ 
dently expect will be upheld. 

In a book like this, trenching upon new ground, 
where every design has been the outcome of 
careful consideration unaided by the experience 
of others, it is not unlikely that errors or am¬ 
biguities may have crept in. The reader who 
finds any such, or who meets with difficulties of 
any sort, will confer a kindness by communicat¬ 
ing them to the author through the publishers. 


F. E. POWELL. 


CONTENTS 


Preface 


PAGE 

iii 


CHAPTER I 

WINDMILL EVOLUTION 

Ancient post-mill. Tower mill. Tower mill 
with regulating or wind-wheel. Modern 
type of windmill. Anemometer. Jumbo or 
horizontal windmill. Wind-motor with ver¬ 
tical axle. The pantanemone. i 

CHAPTER II 

A MODEL WORKING WINDMILL 

Tower mill type. Fixed sails without tail 
regulator. Diameter across sails, two feet. 

Full detailed drawings. n 

CHAPTER III 

A SMALL AMERICAN TYPE WINDMILL 

This type has fixed metal sails three feet in 
diameter, with tail regulator. Develops 
about Ys o H.P. Full detailed drawings.... 22 






vi 


CONTENTS 


CHAPTER IV 

A SMALL WORKING WINDMILL 

PAGE 

Automatically reversing sail type. Diameter 
across sails, six feet. Develops about 
H.P. Suitable for pumping water or for 
running a lathe. Full detailed drawings... 37 

CHAPTER V 

A PRACTICAL WORKING WINDMILL 

A simple and compact wind-power motor with 
adjustable sails and tail regulator. Diam¬ 
eter across sails ten feet. Will develop 
from one-quarter to one-half horse-power, 
according to the velocity of the wind. Suit¬ 
able for pumping water, driving a dynamo 
or light farm machinery. Full detailed 
drawings . 48 

CHAPTER VI 

PRODUCTION OF ELECTRICITY BY WIND-POWER 

Diagram of connections for a wind-driven 
electrical installation. Driving belt ar¬ 
rangement for wind electrical plant. Table 
of wind pressures and velocities 


65 




CHAPTER I 


Windmill Evolution 

It is not a little strange that amateur engi¬ 
neers should have so neglected the windmill, 
either as a subject for model-making and experi¬ 
ment, or even for the more practical purpose 
of power production. Wind-power is free, and 
while it is admittedly erratic it must surely ap¬ 
peal to the mechanical mind as a labour saver 
of some value. The probability is that the lack 
of simple published designs is the main reason 
for this state of things, and the aim of this little 
book is to remedy it. 

Few mechanical appliances have a simpler his¬ 
torical record than the windmill. Until com¬ 
paratively recent years only two main types of 
mill were commonly in use, known respectively 
as the Post and the Tower mills. The former, 
which is the earlier machine, was distinguished 
by the fact that the whole building, carrying 
sails, house, cap, and all machinery, was pivoted 
on a huge timber post, so that the whole struc¬ 
ture had to be removed when it was necessary 
to adjust the mill to face the wind. The Tower 
mill, called also the “ Smock ” and sometimes 
the “ Frock ” mill, was an improvement on the 


2 


WINDMILLS AND WIND MOTORS 



other in having the cap only to revolve, carrying 
with it the sails and (later) the automatic regu¬ 
lating mechanism for bringing the sails round 


Fig. i.— Ancient Post Mill: from an Old Mill at 
Bornholm, Denmark. 

“into the wind” Illustrations of these two 
types of mills are given in figs, i and 2. 

As hinted above, the automatic method of con¬ 
trolling the mill so that the sails should face the 
wind was a fairly recent innovation. It dates 
back to the middle of the eighteenth century, 





WINDMILL EVOLUTION 


3 

when Andrew Meikle introduced the now well- 
known auxiliary regulating wheel, which may 
be seen in fig. 3 



Fig. 2 .— Tower Mill: at Hillerod, Denmark. 


Another advance in windmill construction was 
made in 1807, when Sir W. Cubitt introduced an 
automatic reefing arrangement for the sails. Be- 








4 


WINDMILLS AND WIND MOTORS 


fore that date speed was more or less outside 
the control of the operator, who could only throw 
in or out his machinery as the speed ranged too 



Fig. 3.— Tower Mill with Regulating or Wind Wheel. 


high or too low, or by the application of brakes 
could keep it partly within bounds. 

The later history of the development of wind¬ 
mills must be looked for abroad. The inventor 
of the “ American ” mill is said to have been 
John Burnham, whose location is sufficiently in- 




WINDMILL EVOLUTION 


5 


dicated in the name by which this type is known. 
The date was about the middle of the nineteenth 
century. Everyone knows that the distinction 
between the older types and the modern trans¬ 
atlantic machines lies in the number and dis¬ 
position of the sails, which in the latter are nu¬ 
merous and form a comparatively narrow ring of 
vanes. A modern example of such a mill is 
illustrated in fig. 4. Since Burnham’s day in¬ 
ventors have not been asleep, and the multitude 
of so-called American mills now on the market 
is evidence of their skill. These machines vary, 
however, only in details of design, regulation, 
and control, not in any essential character. 

The American mill, though not much more 
efficient than its older competitor, has the ad¬ 
vantages of cheapness, a more even turning move¬ 
ment, and easier starting. The defects, espe¬ 
cially in the matter of economy, of all types of 
windmills led to a very remarkable series of ex¬ 
periments which were carried out by the Danish 
Government from 1891 until the death of the 
chief investigator, Prof. Poul la Cour, in 1908, 
brought them to an end. The work done by 
this enthusiastic engineer included not only the 
improvement of windmill details, but also a prac¬ 
tical inquiry into the possibility of utilising 
wind-power in the production of electrical en¬ 
ergy. Much of the collected data is naturally 
negative in its results, but students of the sub¬ 
ject must always look with warm admiration on 





6 


WINDMILLS AND WIND MOTORS 


the patient work of La Cour and the good sense 
of the State that assisted him 
As far as this book is concerned, the Danish 


Fig. 4.—Modern Type of Windmill. 



experiments have one special bearing. They 
proved that for maximum power and speed the 
modern multi-sailed machines could not com- 









WINDMILL EVOLUTION J 

pete with a four- or six-armed mill of modified 
design. This type is comparatively easy to con¬ 
struct in a modified form, and has so many ad¬ 
vantages that one or two designs in the follow- 
ing pages have been based upon it. 


Besides the standard types of windmills pre¬ 
viously mentioned, many other wind motors 



Fig. 5. Fig. 6. 

Diagram of Anemometer. Alternative Cups. 

have been suggested and used at times, and de¬ 
serve at least brief notice. One of the simplest 
of these is the ordinary anemometer used for 
measurement of wind velocities (see fig. 5). It 
consists of four hemispherical cups carried on 
cross-arms, which are pivoted at their junction 
and moved by the superior resistance offered by 
the concavity of any one of the cups facing the 
wind. It will of course start in a wind of any 
direction whatever in the plane of its revolution, 
but has no pretension to power production. The 












8 WINDMILLS AND WIND MOTORS 

hemispheres may be replaced by small (tin) 
cones (fig. 6), which are more easily made. 

Another windmill of extreme simplicity, which 
has sometimes been made of a large size, illus¬ 
trated in fig. 7, is called a “ Jumbo/' The small 
illustration in the corner of fig. 7 is a diagram- 



Fig. 7.—“Jumbo,” or Horizontal Windmill. 


matic end view of this type of motor. Arrows 
show the direction of wind and of rotation. The 
action is sufficiently indicated in the sketch, and 
it need only be pointed out that the great dis¬ 
advantage is that it will only work with certain 
winds. It is also necessary to have a large open 
space free from trees or buildings if the best 
results are looked for. 











WINDMILL EVOLUTION 9 

A modified form of the last machine is that 
shown in fig. 8, which has four or more sails 
mounted on a vertical shaft and arranged with a 
semicircular shield which runs on a circular path 
so that the vanes can be acted upon by the wind 
on one side only. Obviously the advantage in 



Fig. 8 .—Wind Motor with Vertical Axle. 


this case is that winds of any direction can be 
made to perform work, but the type has never 
been developed to any extent. 

Another wind motor worth illustrating is, 
however, rather more curious than useful. This 
is the pantanemone, shown in fig. 9. It consists 
simply of two semicircular discs whose diam¬ 
eters are placed at right angles to one another, 
the shaft being between them, in the same plane 
as the diameters, but at 45 0 to each of them. 










10 WINDMILLS AND WIND MOTORS 

The amater may be interested to make a model 
on these lines, which, while without practical 
value, is interesting for the fact that the machine 
will start in wind of any direction. 

Other wind motors there are, of varying inter- 



Fig. 9.—The Pantanem'one. 


est and usefulness, including a quite modern 
development on the lines of a turbine, which has 
not yet seen the light of a manufacturers work¬ 
shop. Space, however, is too valuable to be 
given to any but well-tried designs, although 
much interesting experimental work remains to 
be done in this connection on systematic lines. 





CHAPTER II 


A Small Working Model Windmill. Tower 
Mill Type 

Considering the simplicity of a windmill model 
and the fact that it will not easily get out of 
order, it is surprising that more amateurs do 
not turn their hands to its construction. A 
windmill with sails of only 2 feet diameter, such 
as will now be described, will develop in even a 
moderate breeze fully as much power as an aver¬ 
age steam-engine with cylinder say I inch stroke 
by f-inch diameter, and will therefore be quite 
powerful enough to drive a model workshop, 
work a model crane, or do other similar light 
work. An interesting combination suitable for 
outdoors, where of course the windmill must 
work, would be a model railway arranged on an 
incline so that by means of a long cord the mill 
might be made to draw up a train to the top of 
the slope, the descent being made by gravity. 
This is not the place to enter into details, which 
nevertheless would not be very abstruse and 
would form an interesting problem to be carried 
out by the young mechanic. 

Too much importance should not be attached 
to the idea that wind is unreliable as a motive 


ii 





12 


WINDMILLS AND WIND MOTORS 


force. It will be found more reliable than is 
usually supposed, and apart from that the sim¬ 
plicity of construction, in which no lathe and 
very few tools are required, as well as the ab¬ 
sence of cost in working, should all go to make 
the model windmill a popular object. 

The design shown in fig. io is for a model of 
the size already mentioned, namely, with sails 
24 inches across the tips. It will be of course 
quite easy for the reader to make his model 
either larger or smaller, if he so desires, by tak¬ 
ing care to increase or decrease the dimensions 
of all parts in proportion. In a model like this 
it would only be introducing unnecessary com¬ 
plication if any attempt were made to provide 
the adjustments usual in large mills, and indeed 
it is quite possible that such regulating gear 
would take all the available power of the machine 
to work it. The design therefore dispenses with 
any such elaborations, but the maker can, if so 
disposed, and without any great difficulty, ar¬ 
range for the top of the mill to turn automati¬ 
cally, so that the sails always face the wind. A 
study of the later chapters of this book will show 
how this can be done. 

Almost all the materials used in the construc¬ 
tion are cardboard and wood, so that the model 
is not intended to be left permanently out in all 
weathers. If this should be desired, a larger 
use of wood must be made, and tin or sheet-iron 
well painted should also enter into the construe- 











14 WINDMILLS AND WIND MOTORS 

tion. The baseboard in any case should be a 
substantial bit of timber, weighted if necessary, 
or otherwise, well secured to avoid overturning 
in a strong breeze. 

The main part of tower is formed of stout 
cardboard, which should be well varnished after 
erection. It is cut out as shown in fig. 12, and 
slight cuts along the division lines will enable 
the eight sides to be formed up. A strip of 
stout paper glued inside and outside will com¬ 
plete the joint. Note that the outside strips 
should be cut very neatly and all the same { 
widths. They will then take the appearance of \ 
the finishing boards usually fitted at the corners 
of a wooden building. While still in the flat, 
the various windows, doors, etc., should be pen¬ 
cilled firmly on the different sides, and particular 
care taken to fix any fitments for crane or other 
details. The whole model can be made very 
realistic if some little time is spent in lining out 
the tower and cap to represent weather-board¬ 
ing, or, if preferred, in the case of the tower, 
stone or brick. Pencil lines will be best, and 
colour may be put on to enhance the effect. 
Some idea of the effect to be aimed at is indi¬ 
cated in the lower part of fig. 11. 

The top and base of tower will be octagonal 
in plan, as shown in sketches, fig. 13. 

Details of the head or cap are given in fig. 14, 
which, together with fig. 11, will give a good idea 
of the manner of construction. Fig. 15 shows 

























































































SLIDING BEARING 

Fig. 1 2 - Diagram for Setting-out Tower. (not to scale) 
Fig. 13 - Top and Base of Tower. 

Fig 14 - Views of Head or Cap. 

Fig. 15 - Shape of Card for Roof of Cap. 

Fig 16-Sliding Bearing. .. 














































A SMALL WORKING MODEL WINDMILL 17 

the shape of the two pieces of card to form the 
roof of cap before bending to shape. 

Pieces of cigar-box wood or thin pine form the 
base and ends of cap, and should be joined by 
very thin nails or stout pins, some deal sticks 
about ^-inch square being used as spreaders or 
stiffeners. The ends must be carefully set out 
from centre lines, and holes nicely drilled and 


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SCALE 3" =■ 1 

1 ;t. 


Fig. i7. —Shape of Sail for Model Windmill. 


cut to the dimensions given. Their uses will be 
apparent presently. One side of the roof should 
be made to open with a hinge of calico to enable 
the working parts to be got at. 

Details of the arms and sails are given in figs. 
17, 18, and 19, and readers unfamiliar with the 
“ setting ” of windmill sails should carefully 
study the drawings before shaping the arms. 
As shown in fig. 18, the sails are not placed cen¬ 
trally on the arm, which is much nearer one edge 
than the other. This is shown in the sectional 
view of arm and sail in fig. 18. Then also the 
two sails on one arm point opposite ways, which 
is perhaps best seen in the perspective sketch, 

















l8 WINDMILLS AND WIND MOTORS 

fig. io. The amount by which the sail lies out of 
the plane of revolution is called its “ angle of 
weather.” To obtain this setting, each arm is 
bevelled away, the two ends being bevelled in 
opposite ways. Fig. 19 shows this, and the 
reader has only to imagine each arm brought 
successively into the same position, say the top, 
to realise how the bevel must always be the 
same way with the arm in that position. Fig. 
20 will also be helpful in making this clear. A 
portion of the arm at its middle is left the full 
square section (see figs. 18 and 20, which show 
this). Every care must be taken to make the 
bevelling correctly, or one pair of sails would 
be found bevelled one way and the other in the 
opposite way. This would of course result in 
nullifying the effect of both. The axle, shown 
in various figures, especially 18, 21, and 22, is 
made of a piece of hard wood like oak or hick¬ 
ory, and is shaped specially to take the two arms 
as indicated in fig. 22. Care must be used not 
only to cut this out true and a good fit, but also 
not to break the thin prongs. The shaft must 
be nicely rounded and sand-papered smooth. At 
the collar portion, which will form the forward 
bearing, a little paraffin wax should be melted 
into the grain to reduce running friction, or, 
better still, a thin brass ferrule fitted, as shown 
in fig. 18. 

The arms, in addition to being glued in place, 
must be further secured by wooden pins, and 








































































































































20 


WINDMILLS AND WIND MOTORS 


every care must be taken not only to fit them 
correctly according to the bevels, but also to 
get them dead square with the shaft and with 
each other. The use of an ordinary set-square 
will accomplish this. Both arms, as shown in 
fig. 22, are slightly “ checked ” or “ halved ” into 
each other, both to lock them more securely and 
to reduce the overhang of shaft. Notice should 
be taken that the cutaway is in the back of front 
arm and front of rear arm. 

The sails should be both glued and pinned to 
the arms for security and a pencil line at the 
right place on back of each sail will ensure get¬ 
ting them correctly placed. Each sail, previous 
to being mounted, should have parallel lines, 
about half an inch apart, drawn across both faces 
to imitate the slats generally used in large mills 
of this type. After mounting, and when glue is 
firm, the sails and outer ends of shaft should 
have a couple of coats of good thin varnish to 
enable them to stand some weather. 

It may here be remarked that when pins are 
used instead of nails they will be found much 
easier to drive if a quarter of an inch of the sharp 
point is nipped off. If this is not done, they are 
almost sure to bend. 

It will be seen that the tail end of shaft is pro¬ 
vided with a metal bearing or journal in the form 
of a small headless nail. This must be let in by 
first very carefully boring an axial hole in shaft, 
preferably with a twist drill, the end of shaft 


A SMALL WORKING MODEL WINDMILL 


21 


being bound round to avoid splitting. This jour¬ 
nal runs in a tin bearing (fig. 16), which is made 
to slide stiffly up and down in the slot in back 
of cap. This allows the owner to put in or out 
of gear the winding shaft by means of which 
the mill is caused to perform useful work. This 
is accomplished through the disc A, fig. n, fixed 
on the winding shaft, a rubber band in circum¬ 
ference of disc and thin rubber sleeve on main 
axle being provided to ensure sufficient adhe¬ 
sion. The winding shaft runs in two metal or 
wood bearings, and has the end of a strong 
thread secured to it for a rope. The other de¬ 
tails for the working of this part of the apparatus 
are perhaps shown clearly enough in the draw¬ 
ings. 

If carefully and neatly made, it is wonderful 
how interesting such a model will prove. In a 
stiff breeze the sails will revolve at a great rate, 
and the crane will lift say half a pound at a good 
speed. Weights will of course be in the form of 
small sacks of material, boxes, barrels, etc., and 
the crane should be made capable of slewing so 
that: the loads can be deposited where required. 
Even in the light winds it is of interest to see 
the sails moving gently round, and indeed at 
such a time the appearance is rather more real¬ 
istic, which may partly compensate for the 
lessened utility. 






CHAPTER III 


A Small American Type Windmill 

The design given in this chapter is intended to 
form a link between the model pure and simple 
and the “ small power ” mill able to perform 
solid work. It has been thought desirable to 
admit a certain amount of pattern-making and 
machining in this case, as a windmill of this size 
ought to be made on “ practical ” lines, although 
it is as simple as possible in construction, and 
quite within the range of the amateur with a 
small back-geared lathe. The outside diameter 
of the sails is 3 feet. 

As in all the other cases, the present design 
may be modified here and there to suit individ¬ 
ual fancies, and it may also be reduced to form a 
very pretty model or enlarged to any reasonable 
size. Of course, any such change will involve 
certain alterations in sizes of parts—not neces¬ 
sarily to scale, as, for example, in the case of a 
mill three times the size, the thicknesses of metal 
would not in all cases need to be three times as 
great. 

A small machine like this may be recom¬ 
mended particularly for experimental work. The 
horse-power available in the usual 16-mile breeze 


22 



A SMALL AMERICAN TYPE WINDMILL 23 

may be estimated at %o H.P., but this may easily 
be doubled in any stiffish wind, so that for many 
small matters the power is not to be despised. 
With an efficient pump quite a respectable 
amount of water can be lifted, or an old boiler 
may be pumped up with air pressure, which will 
thus be available for running model steam-en¬ 
gines, or for testing purposes, or even a small 
blow-lamp, etc. There is no reason why a model 
dynamo and accumulator plant should not be 
designed to utilise the power. On an average, a 
breeze of 16 miles per hour or over is available 
for quite six hours a day throughout the year. 
Now a mill of the size here described would run 
a 6-watt dynamo easily, if of good, efficient con¬ 
struction ; so that the normal output for a week’s 
work would be 6 watts X 6 hours X 7 days= 
252 watt-hours, provided the accumulator were 
able to store all it received. Such a result would 
be quite attainable during the majority of weeks 
in a year. 

To get the above result some simple apparatus 
in the way of automatic cut-in and cut-out gear 
would be required, and the cells would probably 
have to be so connected that they could be 
charged in parallel and discharged in series. 
Thus, the stored energy might be utilised at the 
rate of 24 volts, in which case the owner would 
be able to get a return of say 2.5 amperes for 
four hours (24 V. X 2.5 amp. X 4 hours = 240 
watt-hours). Undoubtedly there are many cases 




24 


WINDMILLS AND WIND MOTORS 


where such a result would be regarded as of 
great utility in the amateur’s workshop. Some 
attention will be paid in the later pages of this 



Fig. 23.— Model “American” Windmill: Front View of 
Wheel. 


book to the detailed apparatus necessary to this 
end. 

The American type of mill has been adopted 
in the present instance as much for variety as 
for other reasons. It is not noticeably more 

















STRIP IN END OF AXLE 















































































































26 


WINDMILLS AND WIND MOTORS 


efficient than some other forms, but lends itself 
to simplicity of construction. No attempt has 
been made to have the sails self-regulating, but 
a tail has been adopted in order to keep the mill 
automatically head to wind, and this makes it 



Fig. 27. —Perspective View of Wooden Support for Model 
“ American ” Mill. 

easy to regulate the speed by hand or to throw 
the mill out of work entirely when desired. This 
refinement can, however, be dispensed with if 
desired. The size of the wheel is 3 feet in diam¬ 
eter, and its normal speed in a 16-mile breeze 
should be from 200 to 250 revolutions per minute. 
Front and side views of the complete mill are 
shown in figs. 23 and 24 respectively. The whole 













A SMALL AMERICAN TYPE WINDMILL 2 *J 

of the mill has been designed in metal, as it is 
intended for constant outdoor work in all 
weathers. 

Commencing with the “ tower,” this has been 
reduced to the simplest form by making use of 



Fig. 28.—Plan of the above. 


a piece of old 2-inch gas-, water-, or steam-pipe 
about 3 feet long. It is desirable that this should 
have been galvanised, and it must of course be 
quite straight. The tube is carried in a strong 
wooden framework of 11 X 1 boards and some 
2X2 scantlings, so that it can revolve therein 
without shake or “ give,” since it will form the 
movable part of the mill and will carry the whole 
of the gearing. This wooden framing appears 
in fig. 24, and is further illustrated in perspective 
and in plan in figs. 27 and 28 respectively. 

The construction of the wheel is indicated in 










28 


WINDMILLS AND WIND MOTORS 


the vertical section through it in fig. 25 (which 
is twice the scale of the general arrangement, 
fig. 24), and also in the perspective drawing, fig. 



»A"x Vis" 

GALV. IRON 
STRIPS 
SOLDERED 
TO CIRCULAR 
WIRES 
(*/i# M OR 
No. 6 B.& 8. 
GALVANISED 
FENCING WIRE) 


Fig. 29. —Perspective Sketch of Wheel and Sails of Model 
“ American ” Windmill. 


29. A hub, formed from three pieces of board, 
and turned 6 inches diameter, is secured to the 
shaft by means of an iron strip laid in the saw- 
cuts in end of shaft, as shown in fig. 30. Nails 
or screws make the three pieces of wood practi¬ 
cally one solid whole. 
















A SMALL AMERICAN TYPE WINDMILL 29 
Referring to fig. 29, it will be seen that the 



Fig. 30. —Method of Securing Hub on End of Shaft. 

wheel is carried by arms or spokes of f-inch X 
% 6 -inch galvanised hoop-iron. Six of these 
spokes start from each side of hub, those on the 



Fig. 31.— Wire Rings for Wheel: Upper Diagram, Outer 
Rings; Lower Diagram, Inner Rings. 


front side being made of three full-length strips, 
as seen in figs. 23 and 26. Turning to fig. 25, it 
will be seen how these spokes cross from front 




















30 WINDMILLS AND WIND MOTORS 

to back, and vice versa. They are also soldered 
to four rings, clearly shown in fig, 29, wherever 
they cross these latter, and these rings are so 
designed as to carry the sails between them. 
The rings are of No. 6 B. & S. galvanised fenc¬ 
ing wire, carefully curved to accurate diameters 
—the outer 36 inches, and the inner 18 inches— 
and ends overlapped 2 or 3 inches, bound with 
fine wire and soldered together. The proper 
distances apart of the two sets of rings are if 
inches and J inch respectively, as shown in fig. 
31, which shows also the angle at which the sails 
will lie between them, namely about 25 0 . The 
shape of the sails themselves is shown in fig. 
32: they should be of thin sheet-zinc, the four 
corners slightly bent to lie flat against the wire 
rings to give rather more surface for soldering. 

If the mill is to be used for “ power ” produc¬ 
tion in the ordinary way, it is very difficult to 
find a better means of transmitting the energy 
than by the usual method of bevel-wheels, as 
shown in fig. 24. The exact ratio of one wheel 
to the other is only determined by the require¬ 
ments of the case, and as shown in the drawings 
the vertical shaft would make three revolutions 
to two of the axle. The wind-wheel and its axle 
are carried in a light iron-casting, given in de¬ 
tail in fig. 33, the lower end of which is bored 
out to fit tight on the main 2-inch upright tube. 
The manner of this fitting, and the arrangement 
of bevel-wheels and brass bearings for upper and 
























































































i 

I 



BRASS 

BOLTS 


Fig. 34. Arrangement of Gearing 
and Bearings for Vertical Shaft. 


Fig. 35: Eccentric and 
Rod for Pumping Gear. 


DIAM 


INSIDE 


1 HOLE 


FOR OIL NG 


BRASS 
LOWER END 
BEARING 


LIGHT 


FLATTENED AT 
UPPER END 


LIGHT 
-WOOD ROD 
»/ 4 " DIAM. 


TWO 

%" SCREWS 


j/ 2 SHAFT 




































































































































A SMALL AMERICAN TYPE WINDMILL 


33 


lower ends of vertical spindle, are shown in fig. 
34. There is nothing special in any of these 
parts, which are all simple turned work. 

The machine may be also used to pump water, 



Fig. 36.—Side View of Eccentric for Pumping Gear. 

in which case probably the simplest plan is to 
fit a small eccentric on wind-axle working a con¬ 
necting-rod with a small pump in lower end of 
2-inch tube. To save the reader trouble in de¬ 
signing, a simple eccentric, strap, and rod are 
shown in figs. 35 and 36, giving a lift of ij 
inches, which of course can be varied to suit the 
needs of the maker. Too great a lift must be 
avoided, owing to the speed at which the pump 














34 


WINDMILLS AND WIND MOTORS 


will work. Care must be taken to make the 
casting (fig. 33) higher than shown, if neces¬ 
sary to enable the eccentric to clear (see fig. 35 ). 




Fig. 37.—Elevation and Plan of Tail Regulator. 


Details are given in the drawings, and are prob¬ 
ably clearer than written explanations. 

The tail-gear, by which the mill is made to 
face the wind, is detailed in fig. 37, where the 
upper view is a side elevation and the lower a 
plan. The tail, formed of thin galvanised sheet- 
ii on, is riveted to a piece of very light galvan- 

























A SMALL AMERICAN TYPE WINDMILL 35 

; ised angle of the section shown. This is not the 
usual rolled angle, but bent sheet, much lighter 
and more suitable for this work. It can be ob¬ 
tained from tank-makers or workers in galvan¬ 
ised sheet-iron. The tail is pivoted where shown 
by a bolt which allows sufficient movement and 
is locked in position by the screw shown, a 
tapped hole being provided in the casting (fig. 
33). To get the full effect of wind, the tail must 
lie square with the wheel, or in line with axle. 
Should the wind be too high, its effect on the 
wheel can be diminished by letting the tail turn 
to an angle of 45 0 or less with the wheel, insert¬ 
ing the screw in one of the radial holes in quad¬ 
rant, according to the strength of the breeze. 
The last hole (at right angles to tail) is the 
“ off ” position, as when the screw is in that 
place the tail will lie parallel with wheel and the 
effect of wind on same will be nil. The wire stay 
shown in the drawings supporting back end of 
tail may be found unnecessary, but is easily 
fixed. 

It will be very desirable to fit a brake to the 
mill. This need be only a very simple affair—a 
wooden pulley fitted at any convenient position 
oh the driven shaft, with a rod or lever to press 
on rim either by weights or spring when desired. 
This may often be useful when it is required to 
stop the mill or to alter the setting of tail, or 
even in the workshop to regulate speed when 
experimenting. 




36 WINDMILLS AND WIND MOTORS 

All parts of the mill subject to the weather 
should either be galvanised or very well painted 
if of iron, and a cap of galvanised sheet fitted 
over the bevel-wheels and casting will not only 
avoid unsightly rusting, but will save oil and re¬ 
duce friction. 


CHAPTER IV 


A Small Working Windmill 

The windmill next to claim attention is one 
that should appeal to a large circle of readers. 
It has purposely been designed in a very simple 
form, yet of a size sufficient to develop reason¬ 
able power, namely, %o horse-power in a moder- 
1 ately stiff breeze of say 16 miles an hour. Such 
a mill will do real work, such as pumping water, 
running a small grindstone, or even driving a 
30-watt dynamo. The total diameter of the 
wheel is 6 feet. 

In order to simplify the machine as far as 
possible, the mill has been designed with fixed 
head, so that the wind must be in one of two 
opposite directions to give a maximum effect. 
It should therefore be set up with the front 
wheel facing in the direction of the prevailing 
wind. Where the two principal prevailing winds 
are, say, S.W. and N.W., the best direction for 
the axis of the mill would probably be north and 
south. Local conditions should be studied, and 
detailed records of the prevailing winds of the 
locality can generally be obtained without diffi¬ 
culty. A fixed mill like this is also suitable for 
a town dweller, where long rows of houses con- 
37 








38 WINDMILLS AND WIND MOTORS 

fine the wind to definite directions up and down 
the line of “ back gardens.” 

The vanes (see figs. 38 and 44) can be either 
fixed or allowed to revolve partially upon the 
arms. If fixed, the mill will run in opposite direc¬ 
tions with opposite winds, and while this need 
not matter for such operations as pumping, it 
would not be satisfactory in other work. A 
simple device has therefore been adopted, so 
that when the wind blows from what may be 
called the back of the mill the sails will auto¬ 
matically reverse and so cause the direction of 
rotation to be always one way. The maker who 
prefers to have the sails fixed may ignore this 
arrangement and screw the vanes firmly to the 
arms, which need only to be tapered off, and not 
rounded in section. The alternative arms re¬ 
quired in this case are sketched in fig. 46 (two 
views), and of course require less work on their 
construction. 

The mill, as shown in figs. 38 to 47, has six 
whips or arms mounted upon a triangular hub 
to which they are all bolted. The six whips are 
formed from three hardwood sticks, each mak¬ 
ing a pair of arms. The sticks will be ij inches 
square in section, 6 feet long, the central portion 
for a length of 22 inches left square while the 
ends should be turned down taper, from ij 
inches diameter at the root to 1 inch diameter at 
the tips. Good, sound, straight wood should be 
selected. 




A SMALL WORKING WINDMILL 


39 


n 

;r.l 

ie. 


d 

M 

e 




The hub, shown in detail in fig. 39, should be 
very carefully made, to an equilateral triangle to 
the sizes given, of a piece of very sound hard¬ 
wood of some non-splitting timber. Beech would 
be suitable. The hole for axle must be truly 
bored and fit well so that the sails will all run 
in true plane and square to the axle. The three 
sticks must be bolted to hub, each with two 
f-inch galvanised bolts, with good-sized washers, 
every care being taken to fix each stick at right 
angles to shaft. For further security, another 
f-inch or f-inch bolt will join each pair of sticks 
at their crossing, it being noticed that in one 
case (see fig. 43) a piece of packing of same 
thickness as the sticks will be required. The 
bolt in this case must also be so much longer. 

The axle, or windshaft, as it was called in older 
days, will consist in this case of a short length 
of stout mild steel tubing. The size is not im¬ 
portant—it is shown I inch diameter outside, 
and should not be less. This is not so much for 
strength as for better attachment to the hub 
with its far-spreading sails. A piece of f-inch 
gas tubing will make a satisfactory axle if centred 
in lathe and a light skimming taken off to obtain 
roundness and to make good, clean journals. 

The hardwood hub should be fixed to axle by 
a couple of f-inch split pins going right through, 
as seen in fig. 39. These can easily be got in 
parallel with two of the sticks, and should fit 
well so as to allow no backlash. 





SCALE S A" — 1 ft. 



Fig. 38.— Front View of Sails for 6-foot Windmill (two sails not shown). 
Fig. 39.— Hub to carry Whips. 

Fig. 40.—Diagram of Stops, etc. for Reversing Sails. 






















































































































































42 WINDMILLS AND WIND MOTORS 

The bearings should certainly be of brass, and 
the most simple form they can very well take is 
that shown in fig. 47. This provides, of course, 
no adjustment— a refinement that can be adopted 
with advantage if desired, but which hardly 
needs illustration. These bearings are carried 
in hardwood “ pedestals,” and secured by hard¬ 
wood caps bolted down over them. A recess is 
made in cap and blocks are provided on base to 
prevent side movement of brasses. If possible, 
oil cups or other similar lubricators should be 
fitted, but they may be dispensed with if the oil 
can is kept going. A cover of thin sheet-iron, 
galvanised, may be fitted with advantage to the 
working parts. The details of forward bearing 
are sufficiently indicated in the three views, fig. 
47; the back end bearing being exactly the same. 
Every care should be taken to make all tight 
and avoid any rocking. 

The power of the mill may best be transmitted 
by means of a pair of bevel-wheels, as shown in 
fig. 41. This is the usual method, and of course 
various ratios of speed can be got according to 
the wheels used. As here shown, the wheels 
have a speed ratio of two to one; and a light, 
true-running shaft, say f inch or even -J inch 
diameter, carries the lower wheel. If this shaft 
must be of any great length, or if much of it 
must be unsupported, a greater diameter is de¬ 
sirable; here again tubing can be substituted for 
solid‘rod. For pumping purposes a crank may 



. 1 /" 

14 DIAM. 
1%' # DIAM. > 


y 




CO 


< 

CO 


Q 

LU 




M/v 


a: 

o 


2 

cr 

< 


ll. 

O 


CO 

£ 

UJ 

> 


LU 

h*Q 




o 
aro 
u-z 
< 


f 




Fig. 46 


Fig. 44 Sail Mounted on Whip, with Stops for Automatic 
Reversing, Fig. 45 End View of one Sail and Hinge. 
Fig. 46 Two Views of Arm for Fixed Sails. 





























































































44 WINDMILLS AND WIND MOTORS 

be arranged either as an overhung crank on tail 
end of shaft, by an eccentric as described in the 1 
last chapter, or by cranking the shaft itself, the 
throw being made suitable for the pump to be 
used. .A light wooden connecting-rod should be 
used if this plan is adopted. 

The method of carrying the vanes and also 1 
the device for automatically swinging them to 
suit the wind are shown in figs. 40, 44, and 45. 
The vanes are each formed of one (or, if neces¬ 
sary, of two) f-inch boards, the edges being 
tapered off as shown in fig. 45. Any timber not 
liable to warp in sun and weather will be suit¬ 
able, one of the best being Californian redwood, j 
usually obtainable in wide sizes. 

The supports or hinges, clearly seen in fig. 44, | 
are of f-inch X f-inch galvanised hoop-iron 
neatly bent to fit round the arms at the places 
assigned to them. They are attached to the 
vanes by f-inch flat-headed rivets or bolts, gal¬ 
vanised by preference, with large washers next 
the wood, as shown. A good screw projecting j 
from the arm just beyond each bearing prevents j 
the vane from slipping off. It should be seen 
that each vane swings easily but without shake. 

Owing to the unbalanced shape of the sails, j 
they will swing according to the direction of 
the wind, and means are provided to allow them 
to take up a position either way at the best angle 
for general work. This is specially shown in fig. 
40, in which the black lines show how the sails 






















































































































































46 WINDMILLS AND WIND MOTORS 

would set with the wind in the direction given, 
and the direction of rotation for same. The 
dotted lines indicate the condition when the wind 
blows from the opposite quarter. The device 
consists of pairs of short cross-bars screwed to 
backs of arms and bolted, with packing between, 
at their crossing. As the angle each way is im¬ 
portant, care must be taken, by cutting away the 
cross-bars or providing packing, if either is 
necessary, to secure an angle of about 25 0 . A 
template cut to the correct angle should be used 
to adjust the vanes in each case. 

The timber framing on which the mill is 
erected needs no description beyond that af¬ 
forded by the sketches, but it should be remem¬ 
bered that stiffness is essential not only for 
Safety but also to avoid strain on the vertical 
shaft and loss of power. Cross-bars can be 
bolted in at intervals if this shaft is long, and 
bearings fitted upon them. 

A final word is necessary as to painting. For 
such an “ outside job ” as a windmill careful 
painting is essential, and in particular each piece 
of finished timber in the mill itself must be very 
carefully painted over before being built up. 
Three coats of the best paint will not be too 
much, and the last coat may be advantageously 
mixed with some thoroughly good “ outside ” 
varnish. The next season after erection, another 
two coats of paint should be applied, but prob¬ 
ably longer intervals may then elapse between 



A SMALL WORKING WINDMILL 


47 


the applications. Attention should always be 
paid to regular oiling, and it will be wise to 
avoid working the mill unnecessarily by fitting 
a brake or locking mechanism in some convenient 
position indoors. Indeed, a brake may be very 
desirable as a means of preventing accident either 
to work or person if the windmill is used for 
driving a lathe or other machine. 






CHAPTER V 


A Practical Working Windmill 

To complete the series of small windmills suit¬ 
able for amateur workmanship, a really practical 
machine, capable of “ power ” production on a 
moderate scale, remains to be described. It is 
thought that a mill of io-feet diameter, while 
probably taxing to the fullest the constructive j 
ability of any average reader, might well be at¬ 
tempted by a serious worker with happy results. 

In this instance, while preserving the general 
principle of simplicity, completeness has been 
aimed at, and castings and forgings are adopted 
throughout without hesitation. This certainly 
involves some pattern-making, which, however, ■ 
should be within the scope of any one able to 
carry out the necessary machining of the cast- ] 
ings. Some readers may be willing—and able— 
to reduce this part of the labour by adopting ] 
makeshift details, but it should be remembered 
that such a method is hardly more advisable J 
than it would be in the case of building any 
other motor—say a steam-engine—for power 
production. 

The rating for a io-foot windmill would be 
about J H.P., which probably appears small for 








































































50 WINDMILLS AND WIND MOTORS 

the amount of work involved and the material 
employed. It is, however, a conservative esti¬ 
mate, and is based on the standard 16-mile 
breeze, which holds good for something like 8 
hours per day on two-thirds of the days in the 
year. Manufacturers probably rate a mill of 
this size much higher, and as long as no wind- 
velocity is stated, they may fairly claim to be 
correct. All practical modern windmills, how¬ 
ever, are constructed with automatic gear so 
that with any given velocity of wind a maxi¬ 
mum output is obtained, and any increase in the 
wind is more or less counteracted by the action 
of the automatic gear. It follows therefore that 
if our io-foot mill is set to produce say \ H.P., 
it can only do this with a wind of much higher 
velocity than 16 miles per hour, which is also 
much more rare. Nevertheless, it will be quite 
within the maker’s power to get as much as this 
and more out of his machine, if he so desires 
and the wind is there. It will be merely a ques¬ 
tion of altering the controlling weight, but will 
also involve very much heavier stresses on the 
machine. This point must be borne in mind. 

A general elevation is given in fig. 48, to a scale 
of J inch to the foot. The tower is built up of 
four 3 inches X 3 inches vertical members, 12 
feet high, each placed at the corners of a square, 
with 4-inch space between each pair of uprights. 
These uprights are well braced by struts, also 
of 3 X 3 timber, starting below the circle of 


ld>»HS 
















































































































































































































































































A PRACTICAL WORKING WINDMILL 


53 


vanes, one strut on each side, and each bolted 
to two uprights, as shown. The lower ends of 
struts are lodged into two horizontal diagonals, 
which are halved over each other at their cross¬ 
ing so as to lie level. The lower ends of uprights 
with a little shaping will also fit alongside these 
diagonals and must be securely bolted to them 
with ^-inch bolts. Bolts or straps must also se¬ 
cure the diagonals to the feet of struts. Four 
J-inch bolts not less than 3 feet long must be 
carried down at the four ends of the horizontal 
members, into pockets of rough concrete of 2 or 
3 cubic feet each. The holes above the concrete 
must be then very firmly filled in and rammed, 
and if the ground is soft or yielding, a greater 
depth and more concrete must be employed. It 
is perhaps needless to insist on the importance 
of having all this timber, but especially that in 
contact with the ground, thoroughly well tarred, 
or better still, properly creosoted, and all bolts 
should be galvanised. Large thick washers 
under the nuts of the f-inch bolts are required. 

A more detailed side elevation of the head, 
tail, and part of the arms is given in fig. 49, to 
a scale of f inch to the foot. This shows the 
movable head casting A carried on the bearing 
casting B. Both these are detailed still further, 
to a scale of ij inches to the foot in figs. 50 to 
54, and require little explanation. The stem of 
A is of course turned to ride easily in the bored 
hole in B, and is fitted with brass bushes for 





54 


WINDMILLS AND WIND MOTORS 


axle and for vertical shaft. The casting B is 
securely bolted to the tops of the 3X3 uprights 
with ^-inch bolts, care being taken to get it 
truly upright and central with the timbers. 
Packing pieces, C, in figs. 49 and 54, are used to 
ensure correct spacing. Note should be taken 
of the sheet of zinc or lead, D, figs. 49 and 50, 
which is first laid on tops of uprights, with suit¬ 
able hole in middle to allow stem of B to pass, 
and is then dressed down, as shown, to throw 
all water from the timbers. It should hang clear 
of the latter to avoid capillary action. 

The tail, employed to keep the mill up to the 
wind, is also shown in fig. 49 at E. It is car¬ 
ried by two light angles, ij inches X inches 
X 4 inch, F and G, which are bolted respectively 
to the top and bottom of head casting A with 
f-inch bolts. The position of these angles is in¬ 
dicated (in dotted lines) in figs. 50 and 51 at F. 
A sheet of zinc forms the tail surface and is 
riveted to angles with J-inch rivets about 4^ 
inches’ pitch. Four stiffeners of ij inch X i~ 
inch hoop-iron run vertically across the surface, 
dividing it into three equal spaces. Both angles 
and stiffening strips should be galvanised. 

The shaping of one of the eight arms for the 
vanes is shown in fig. 55, and the outline of sail 
in fig. 56. The assembling of these parts is in¬ 
dicated in fig. 49, but it is necessary to turn to 
fig- 5 7 to see in greater detail not only the 
method of fixing but also the formidable-looking 


A PRACTICAL WORKING WINDMILL 


55 


array of levers and rods constituting the auto¬ 
matic gear. Every one of the eight sails has its 
independent set of levers to actuate the central 


f/> x 2 „ 



Fig. 55.— Shaping of Arm or Whip. 


sliding rod, but while it must be admitted this 
means a rather long list of troublesome details, 
the complication is much more apparent than 
real, and is largely due to the difficulty of ren- 



Fig. 56.—Outline of Sail for io-foot Windmill. 


dering in a drawing the working of levers that 
do not lie in the same plane. The reader is 
therefore asked to study with some care these 
drawings, which the author for his part believes 
to be presented as simply as possible. All that 
has really to be remembered is that the wind 






























56 WINDMILLS AND WIND MOTORS 

impinging on an unbalanced sail attempts to 
turn it on its hinges, as shown in plan in fig. 58. 
Regarding now the short side of sail (the so- 
called “ leading sail”), it of course describes an 
arc of rather less than a right angle, until it 
lies flat in the plane of the wind’s direction. The 
chord of this arc, or rather of that described by 
a projecting pin J (a piece of % 6 -inch rod bent 
as shown), forms the path of the lower arm of 
lever K, fully drawn in fig. 64, the other arm of 
which, being at right angles, must move verti¬ 
cally up and down as compared with the sail 
movement. This actuates the f-inch rod L (de¬ 
tailed in figs. 59 and 60), which in its turn works 
lever M. As before indicated, the planes of 
movement of the levers K and M are not coinci¬ 
dent, but while this makes their representation 
on paper less easy, it in no way affects the ob¬ 
ject, which is to produce on the sliding rod N 
an in-and-out movement according to the amount 
of the wind’s pressure. The lever K is supported 
at the special angle required (seen in plan in fig. 
58) by a bracket O (fig. 64) bolted to arm. The 
top arm of lever is made with a return end in 
order to give a long bearing, and bottom end 
slotted to allow the necessary play for the pin 
J, due to the path of the latter being an arc. 

Returning now to the sliding rod N, it will be 
seen that the motion of the eight levers M is 
transmitted to it through the special turned nut 
P, figs. 62 and 63. The various possible posi- 


A PRACTICAL WORKING WINDMILL 57 

tions of the forked end of lever require that the 
section of this “nut” be turned to the curves 
shown. A lock-nut on the outer side enables P 
to be screwed up to the most suitable position, 
and there secured in place by the lock-nut. 

Examination will show that the tendency of 
any wind action on the sail is to force rod L 
nearer the centre of mill, and so to drive rod N 
to the right as looked at in figs. 49 and 57. This 
has to be met at the other end of N by the coun¬ 
teraction of a weight, R, carried by a cranked 
lever, S, indicated in a diagram in fig. 49, and 
more fully in figs. 67 and 69. The lever, the 
short end of which is doubled or looped (see left- 
hand view in fig. 67) in order to pass on both 
sides of the loose pin bearing T, is hung from 
the upper tail-angle F by a -J-inch screw, a se¬ 
curer bearing being obtained for this by tapping 
into the block U, which is riveted to angle, see 
section, fig. 68. The arrangement of end of rod 
N and pin block T is more clearly shown in fig. 
69. Fig. 65 gives an end view of pin bearing, T. 

The weight, R, should be cast double, one 
piece having a slot or recess cast on one side as 
shown in fig. 66. It is difficult to fix on the exact 
weight that may be required, as this depends 
not only on the views of the maker as to the 
power which he desires the mill to exert at its 
maximum, but also on the friction of the numer¬ 
ous joints in levers. It is, however, recom¬ 
mended that a trial be made with a weight of 


Fig. 59 



Fig. 57. — Arrangement of Automatic Regulating Gear for 10-foot Windmill. 

Fig. 58.— Plan of Inner End of Sail, showing extreme positions. 

Figs. 59 and 60. — Two Views of Push Rod L and Lever M. Fig. 61. — Pin Bear¬ 
ings for Levers M. Figs. 62 and 63. — Turned Nut on Sliding Rod N. 


































































































































































































6o 


WINDMILLS AND WIND MOTORS 


about io lbs., corresponding with the full lines 
in the drawings given. If the mill sails are 
found to open too easily with this weight—which 
is, however, doubtful—it can be shifted further 
along the lever arm, or if even this is found 
insufficient, another disc can be added as shown 
dotted on the left in fig. 66. A light galvanised 
chain, running over a pulley in top angle of 
tail and hanging with a loop to within 6 feet of 
the ground level, is used to lift weight when the 
owner desires to stop the mill, this action, of 
course, opening all the sails so as to present only 
their edges to the wind. The other end of chain 
is looped back to a point near outer end of tail 
to avoid entanglement with uprights or running 
shaft. A hook attached to chain in proper posi¬ 
tion, W, can be hitched under lower angle of 
tail by taking chain sideways a little and so hang 
the weight up for any length of time. 

The automatic action and its details should 
now be fairly clear, and the remaining parts of 
the mill are simple. The large central casting, 
X, appears in several figures, notably in section 
in fig. 57 and in front elevation in fig. 70. It is 
undoubtedly the most serious undertaking in the 
whole construction and must probably be “ put 
out ” into the hands of professionals. It should 
not, however, be a costly item, and if made as 
indicated will go far to making the mill a prac¬ 
tical job. This casting carries the eight arms 
and makes secure connection to the axle. It is 




SCALE l7 2 "= 1 FT. 




■iiffiflmim - ■ -- - — 

(TWO NUTS LENGTH 8TRAIGHT 22 ' 

Fio. 72— Straining Rods for Arms. 































62 WINDMILLS AND WIND MOTORS 

backed up in its support of the arms by the 
smaller annular casting Y, fig. 71, which is bored 
to fit well over turned part of X. Three very 
well-fitted ^-inch screws at 120° secure the boss j 
to shaft, a good tight fit between shaft and casting 
being essential. These screws must not project 
inside the shaft far enough to touch the sliding ] 
rod N. 

The casting X carries also the eight little 
brackets Z for the levers M. These brackets are 1 
of cast iron and may be “ American ” in char- 1 
acter in so far that the pins form part of the ~ 
casting, a file probably being a good enough tool 1 
to finish them. 

A little further stiffening of the sail-arms is 1 
obtained by the use of the tension-rods TR, de¬ 
tailed in fig. 72. These are only J-inch galvan- I 
ised rods one end turned over for an inch at 
right angles and the other screwed and lock- i 
nutted. The tension put on these must be even 
and not too great; but they, as well as other ( 
screws and bolts in the machine,' will probably 
require tightening up once or twice when the 
weather has had its effect on the timber. 

A word is required in reference to this latter 
item. The arms should certainly be wrought 
from good sound seasoned ash. The sails can 
hardly be formed of better timber than Califor¬ 
nian redwood (Sequoia semper virens), which 
can be obtained in wide boards. They will be 
i inch thick with the edges chamfered off both 





A PRACTICAL WORKING WINDMILL 63 

sides. Three battens, 2 inches X ij of sound 
hardwood (ash, bluegum, etc.) must be well 
screwed across, and the hinges, three in number, 
will come opposite these, on the other side of 
sail. These hinges should be of the strongest 
make of T shape, galvanised. They are shown 
in the plan, fig. 58. 

So far the axle has hardly been mentioned. 
It is, however, a very simple matter, being 
nothing but a piece of 2-inch (outside diameter) 
steel steam-pipe, preferably solid drawn, and 
quite i inch thick. It should be true to begin 
with, so that the very lightest skimming in the 
lathe will make it a good journal. It carries the 
usual bevel-wheel, indicated in figs. 49 and 57, 
and gearing with another of the same size on 
the vertical shaft. Both wheels are 4 inches on 
inner diameters, but may be more or less if re¬ 
quired, the casting A being altered if necessary. 
The vertical spindle would be a piece of f-inch 
cold rolled steel shafting, and should have bear¬ 
ings also at bottom end and half-way down the 
tower, presuming the spindle is carried down to 
the ground as shown in fig. 48. A pair of bevel- 
wheels is also required to transmit power to a 
horizontal shaft. 

One or two points in conclusion deserve re¬ 
mark. First, that all possible metal parts should 
be either galvanised or of sheet zinc. The cast¬ 
ings will most probably be only painted. They 
should be “pickled,” freed from rust and espe- 


64 WINDMILLS AND WIND MOTORS 

dally from dirt and grease, and painted with 
good red lead paint well rubbed in. It is better 
still to warm the castings to about ioo° Fahr. 
when putting the first coat on. Three coats of 
the red lead paint, thinly put on, and a finishing 
coat of grey or black paint are required to make 
a good job. The woodwork, it has already been 
remarked, should be tarred or creosoted. This 
does not apply to the arms and vanes, all of 
which require the usual painting in most thor¬ 
ough fashion. The most suitable paint is pure 
white lead with a dash of ochre. 

Steps, formed from any suitable timber, say 
3X2 inches, should be nailed up at least two 
sides of the verticals to enable the owner to 
reach the head of mill for oiling, etc. 

A mill of this power, especially if used to 
drive a lathe or other workshop tools, should 
have a simple cut-out device—such as a sliding 
coupling actuated by a handy cord or chain, so 
as to throw the mill out of gear in case of an 
accident. A brake is not so necessary, as the 
automatic gear is designed as much as possible 
to keep the machine at uniform speed. Under 
normal output this speed should be from 80 to 
100 revs, per minute, varying slightly according 
to the setting of the sails. These, in their flat¬ 
test position—that is, with a light wind—should 
lie at an angle of about 20° to the plane of 
revolution of the wheel. 


CHAPTER VI 


Production of Electricity by Wind-Power 

To most readers the possibility of applying 
the power from a windmill to the production 
of electrical energy will be an interesting fea¬ 
ture, and it is fortunate that recent experimental 
work has proved that not only is this feasible 
but even simple, inexpensive, and reliable. By 
“ reliability ” it is not, of course, meant that the 
fickleness of the wind is completely overcome, 
but only that the apparatus, which includes 
some automatic gear, can be relied upon not to 
go wrong. It is certainly possible—within rea¬ 
sonable limits—by employing a large enough 
mill and accumulator, to tide over even exten¬ 
sive calms, but probably any amateur engineer 
who decides to adopt the method to be de¬ 
scribed will be willing to accept a few inevitable 
“ off-days ” in each year, when no current will 
be available, balancing this trouble against the 
very definite advantage of the inexpensiveness 
of the power. 

Many experiments have been made at differ¬ 
ent times and in different places to utilise wind- 
power in the way now under discussion. There 
is, however, no need to deal with more than one, 
65 


66 


WINDMILLS AND WIND MOTORS 


which, having proved satisfactory in practice, is 
in use in a fairly large number of instances in 
North Germany and in Denmark, not only for 
the supply of isolated farm-houses but even for 
village lighting and power production. In prac¬ 
tically all these cases an oil-engine is used as a 
standby, yet it is found that the number of days 
in the year on which this engine is called into 
use are so few that the reader who proposes to 
light a house or provide himself with power on 
a small scale may reasonably consider the extra 
expense unnecessary in his case. 

The following suggestions are based entirely 
on the excellent work recently done and pub¬ 
lished by Prof. P. la Cour in Denmark on behalf 
of that Government, which has in that partic¬ 
ular placed itself ahead of other countries— 
considerably to the advantage of many of its 
villages and isolated dwellings. The reader 
must be prepared to experiment a little—not 
indeed in principles but in details of apparatus 
to suit his own case—but may rest absolutely 
assured that the method is quite practical and 
satisfactory. 

There are two main difficulties in applying a 
power so variable and intermittent as wind to 
the production and supply of electricity. There 
must, first, be a means of automatically switch¬ 
ing on the dynamo to a set of accumulators 
whenever the former is in a position to deliver 
current, the same apparatus cutting it out when 


PRODUCTION OF ELECTRICITY BY WIND-POWER 67 

the power falls away. Secondly, means must be 
adopted whereby an increase of wind-power be¬ 
yond the normal amount required to just work 
the dynamo shall not affect the output by in¬ 
creasing either voltage or current. Both these 
ends have been attained by La Cour with the 
simplest apparatus imaginable. 

A consideration of the second question raised 
will show why it is necessary to decide on a 
definite wind-velocity as being that at which 
any given windmill shall supply its “ normal ” 
output. By rating it low, say a wind of 9 miles 
per hour, it is possible to keep a dynamo work¬ 
ing nearly every day in the year and for twelve 
hours out of the twenty-four. But the power of 
the wind at 9 miles an hour is only a quarter 
of that at 15 miles an hour, and although the 
latter only blows about half the total number 
of days in a year, and then for only about nine 
or ten hours a day, its total output is greater 
than the other. Another point to be considered 
is that a very small dynamo is much less effi¬ 
cient, so that a double loss is experienced if too 
much constancy of work is aimed at. Of course, 
in a large installation these points have less 
emphasis, and it becomes desirable to run the 
plant at a lower wind-rating (in other words, 
use a comparatively large mill), the only limit¬ 
ing factor being the initial cost of the plant. 

In a wind-driven generating plant the follow¬ 
ing points should be noted. The windmill itself 


68 


WINDMILLS AND WIND MOTORS 


should be self-regulating (as, for example, that 
described in Chap. V.), and fitted with tail so as 
to turn to face all possible winds. The dynamo 
should be shunt-wound, so that an increase in 
the external resistance tends to raise the ter¬ 
minal voltage. If necessary, this tendency may 
be increased by having one or two resistance 
coils in series with the shunt-winding, these 
coils being automatically cut out as the external 
resistance rises and current falls. A low-speed 
machine is certainly preferable, the speed of a 
windmill being rather low itself. The accumu¬ 
lator is a vital point: it should have a large 
capacity, as on this depends its ability to main¬ 
tain a supply over a longer period of calm; yet, 
as it is undesirable for any accumulator to re¬ 
main long at a low state of charging, care must 
be taken to avoid draining it—especially if a 
spell of calm weather seems likely. 

The whole of the electrical apparatus is 
shown diagrammatically in fig. 73, the only part 
needing much description being the automatic 
switch, further illustrated in three views in fig. 
74. This consists of two electro-magnets, EM, 
each like an ordinary bell-magnet, and wound 
with fine wire, but with an extra winding of a 
few turns of thick wire, exactly like a compound- 
wound dynamo field magnet. A horse-shoe per¬ 
manent magnet, PM, is suspended so that its 
poles lie opposite and near to the poles of the 
electro-magnets, and swings by means of the 












































































70 


WINDMILLS AND WIND MOTORS 


pivot screws which work in a brass (or non¬ 
magnetic) block, B. This block also carries the 
copper rod CR, each end of which turns down¬ 
ward into the wooden cups I and 2, containing 
mercury, matters being so arranged, however, 
that the end 1 is always in the mercury which¬ 
ever way PM is swung, while 2 only touches 
the mercury when that end of CR is drawn 
downwards. 

The switchboards present no special features. 
By following out the connections it will be seen 
that any agreed number of cells can be switched 
on to the dynamo, while any independent num¬ 
ber can be caused to supply the lamps. This 
latter arrangement is desirable to allow for drop 
of voltage during discharge, also to provide for 
losses in mains and for an extra cell or two in 
case of accident to others. 

The action of the automatic switch is as fol¬ 
lows : Assuming the dynamo to be still, or 
running at too low a speed to furnish current, 
it will be seen that the battery is energising the 
electro-magnets EM through the fine wire-coils, 
the current passing also through the armature 
of the dynamo. The winding of EM is such 
that the current in this direction attracts the 
poles of PM to the right and so raises the end, 
2, of CR out of the mercury. Only a very 
small current is required, or allowed, to be thus 
wasted. Supposing now the wind to increase 
sufficiently to raise the speed of dynamo so 































































































































































































































































72 WINDMILLS AND WIND MOTORS 

much as to be able to supply current, the first 
effect will be to reduce the current in EM to 
nil and then to reverse it, altering the polarity 
of the electro-magnets and throwing the lower 
end of magnet PM over to the right. This, by 
dipping the end 2 of CR into the mercury, 
makes connection between the dynamo and ac¬ 
cumulator, the charging of which at once begins. 
The effect of the thick-wire coils on EM is to 
hold the magnet switch more securely during 
charging. The opposite action—that of throw¬ 
ing out the dynamo when the speed fails—is 
obvious on inspection. 

The apparatus required to maintain the dy¬ 
namo at the right speed when that of the mill 
itself ranges too high is a system of belts and 
pulleys, shown in fig. 75. Here A is an ordinary 
pulley with the usual curved face; B, a rather 
wide, flat-surfaced pulley; C and D, again, ordi¬ 
nary pulleys; G and B being fast on one shaft. 
This shaft is carried on the light timber frame 
EF, hinged at E, and carrying a weight G at 
the other end. 

It will be seen that this arrangement provides 
for a constant pull on the belt between A and B. 
It may be found that this pull is too great even 
without the weight G, in which case a cord 
(shown dotted) takes its place, and, by means 
of a pulley overhead and another weight, takes 
off some of the load. 

The belt CD has no special feature beyond 



PRODUCTION OF ELECTRICITY BY WIND-POWER 73 

being thin, supple, and even. That between A and 
B, however, must be specially smooth on its run¬ 
ning surface, and must in addition be thoroughly 
well oiled. On this depends the peculiar result to 
be obtained. It is found that when the weight G 
has been properly adjusted, and other details of 
current supply, etc., decided upon by experiment, no 
matter how much faster than normal A is compelled 
to run by the wind, the speed of B remains con¬ 
stant or with just sufficient variation to meet 
the slightly varying conditions required by the 
dynamo, the belt slipping on B at the higher 
speeds. The principle, of course, is not new; 
but its application in the present instance, to¬ 
gether with the automatic switch, is an excellent 
example of mechanical adaptation. 

The details of the whole of the apparatus 
must necessarily be worked out by individual 
requirements: the following suggestions, how¬ 
ever, are added as an example, the instance 
chosen being the io-foot windmill described in 
the last chapter. This windmill, working in a 
15- or 16-mile breeze, should have an output of 
about J H.P. Allowing for losses in dynamo, 
gearing, and belts, it may be assumed that a 
dynamo of 100-watts output would be the right 
machine for the available power. The voltage 
chosen might well be 25, this being its lowest 
rate at normal speed, which may be assumed at 
1500 revs, per minute. 

Under these circumstances, and assuming 





74 WINDMILLS AND WIND MOTORS 

pulley A (fig. 75) to run at 200 revs, per min¬ 
ute (by whatever gearing used), A might be 12 
inches diameter X 2 inches width; B, 6 inches X 



Fig. 75. —Driving Belt Arrangement for Wind Electrical 
Plant. 


3 ; C, 8 inches X 2; and D, the dynamo pulley, 
2 inches X 2 inches. This gives a rather higher 
ratio than is required—an error on the right 
side. The belt between A and B should be 1 y 2 
inches X s Ag inch, the pulleys being about 6 feet 
centres, and belt CD I inch wide X % inch thick, 
also with about 6 feet drive. 


































PRODUCTION OF ELECTRICITY BY WIND-POWER 75 

There would be twelve accumulator cells, 
each of from 150 to 200 ampere-hour capacity, 
which would be easily capable of dealing with 
the full current for twenty-four hours’ continu¬ 
ous charging. The capacity mentioned is the 
maximum suitable for the given plant, but the 
minimum may be anything down to twelve 
pocket-batteries, if so desired. Within the 
limits given, the greater the capacity the more 
the independence of conditions of wind. 

With regard to the automatic switch, a little 
experimenting and adjusting will be needed to 
ensure its correct working. The electro-magnets 
may be two ordinary bell-magnets, wound with 
No. 36 wire, the bobbins being about ij inches 
long and 1 inch diameter outside. A resistance 
may be needed in series with this winding, or 
the effect may be tried of connecting up only 
six of the cells to these coils, the six on the left- 
hand side in fig. 73 being, of course, selected. 
All four bobbins will be joined in series. Over 
the fine wire on each bobbin will be wound from 
six to twelve turns (to be determined by experi¬ 
ment) of No. 16 or 14 gauge cotton-covered 
wire, the winding being in same direction as 
the fine wire in each case, so that the current 
is a reinforcing one when being supplied from 
the dynamo. The balance of the permanent 
magnet can be adjusted by moving the copper 
rod CR either to right or left. 

The output from such an installation may of 




76 WINDMILLS AND WIND MOTORS 

course be anything up to the safe discharge rate 
of the battery employed. Assuming the normal 
conditions of charging to be, say, ioo watts for 
ten hours (equal to 1000 watt-hours), and that 
this charge is to be used in two evenings, there 
would be available 500 watt-hours per evening, 
less the losses in transforming, or, say, 80 watts 
for five hours. Fortunately at the time of year 
—winter—when longer lighting is necessary 
more wind-power is also available. Of course, 
only metallic-filament lamps should be used, 
when it will be seen that with proper propor¬ 
tioning of the plant quite a respectable output 
in light is to be obtained. The lamps for the 
above installation would be 16 volt. 

If the loan of an anemometer cannot be ob¬ 
tained, a simple form of wind-pressure meter 
should be used to determine the right weight 
(R, fig. 49) required to just hold the windmill 
sails at the velocity decided upon. Such an 
apparatus is sketched in fig. 76. It is merely a 
sheet of stout cardboard, 2 feet X 1 foot, hung 
on one of the narrow edges by a hinge of linen, 
the middle of the lower edge being connected 
as shown to a small spring letter balance capa¬ 
ble of reading up to at least one pound. A table 
of wind-pressures and velocities is given below, 
by which any pressure registered can be con¬ 
verted into velocity. The pressure-board must, 
of course, squarely face the wind blowing at the 
time of the experiment. Note that the spring 


PRODUCTION OF ELECTRICITY BY WIND-POWER 77 

balance is just at zero when no wind is im¬ 
pressed on the board, or a false reading’ may 
be obtained. If made to the given sizes, the 



Fig. 76.—A Simple Wind-pressure Gauge. 

readings will be direct measurements of the 
pressure per square foot. 

The brake horse-power of a windmill can be 
taken in exactly the same way as that of a 
steam-engine, the only difficulty being the usual 
unsteadiness of the wind. At a time when the 
wind is fairly steady and about right in velocity, 











7» 


WINDMILLS AND WIND MOTORS 


such a test should be made, one observer watch¬ 
ing the pressure-meter and noting the pressure, 
say, every half-minute, another reading the 
spring balance of the brake at similar intervals, 
the test lasting for a quarter of an hour. Aver¬ 
age results may then be obtained, which may 
be extremely useful for determining the size of 
dynamo required, it being remembered that the 
power of the wind varies (theoretically) directly 
as the cube of its velocity. In practice the vari¬ 
ation rate lies between this and the square of the 
velocity. 


Table of Wind Pressure and Velocities. 


Miles per 
hour. 

Feet per 
minute. 

Feet per 
second. 

Force in 
lbs. per 
sq. foot. 

Description. 

1 

88 

1.47 

.005 

Hardly perceptible. 

2 

3 

176 

264 

2.93 

4.4 

.020 ) 
.044/ 

Just perceptible. 

4 

5 

352 

440 

5.87 

7.33 

.079 ) 
.123/ 

Gentle breeze. 

10 

15 

880 

1320 

14.67 

22 

.492) 

1.107/ 

Pleasant breeze. 

20 

1760 

29.3 

1.968 ) 

Brisk gale. 

25 

2200 

36.6 

3.075/ 

30 

2640 

44 

4.428 ) 

High wind. 

35 

3080 

51.3 

6.027 / 

40 

45 

3520 

3960 

58.6 

66 

7.872) 

9.963/ 

Very high wind. 

50 

4400 

73.3 

12.300 

Storm. 

u0 

5280 

88 

17.712) 

Great storm. 

70 

6160 

102.7 

24.108 / 

80 

7040 

117.3 

31.488) 

Hurricane. 

100 

8800 

146.6 

49.200 / 









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WINDMILLS AND WIND MOTORS. By F. E. Powell. A 
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with descriptions of inexpensive home-made apparatus neces¬ 
sary for this art. By Edward Thatcher. Contents of Chap¬ 
ters:—1. Soldering. 2. Soft Soldering. 3. Methods of holding 
work. 4. Hard Soldering and brazing. 5. Cleaning up work, 
polishing. 6. Standard Apparatus. 7. Home-made apparatus. 
84 pages; 52 illustrations. 

TELEGRAPHY FOR BEGINNERS. The Standard Method. 
An Authoritative book of instruction in the methods and forms 
most approved, with a series of lessons. By Willis H. Jones, 
With the Morse alphabet and the Continental code. 64 pages 
19 illustrations, paper binding, 25c.; cloth binding, 50c. 

THE CORLISS ENGINE, AND ITS MANAGEMENT. By J. T. 
Henthorne and C. D. Thurber. *A practical little handbook for 
the instruction of young engineers, showing them how to take 
indicator cards, set the valve and run a Corliss engine. 95 
pages; 24 illustrations. 

THE A, B, C OF THE STEAM ENGINE. With a descrip¬ 
tion of the Automatic Governor. By J. P. Lisk. With six large 
J scaled illustrations, all numbered and named. The engine is a 
well-known American type of high-speed engine. With descrip- 
| tive notes. 

MAGNETS AND MAGNETISM. Simply Explained. By A. 
W. Marshall. Contents of Chapters:—1. The Theory of mag¬ 
nets. 2. Permanent magnets. 3. Electro magnets. 4. Solenoids 
or tubular electro-magnets. 5. Experiinents with magneto. 
A very clearly written explanation of an important subject. 88 
pages; 49 illustrations. 






25c. BOOKS. 


ELECTRICITY. The study of, and its laws for beginners, com¬ 
prising the laws of electric current generation and flow, Ohm’s law, 
galvanism, magnetism, induction, principles of dynamos and motors, 
wiring, with explanations of simple mathematics as applied to elec¬ 
trical calculations. By N. H. Schneider. With 55 original illustra¬ 
tions and 6 tables. 

DRY BATTERIES. A practical handbook on the designing, fil¬ 
ling and finishing of dry batteries, with tables, for automobiles, gas 
engine, medical and coil work, electric bells, alarms, telephones, ex¬ 
periments and all purposes requiring a first-rate battery. Fully il¬ 
lustrated with 30 original drawings. 

ELECTRICAL CIRCUITS AND DIAGRAMS. Being a selec¬ 
tion of original up-to-date and practical diagrams for installing an¬ 
nunciators, alarms, bells, electric gas lighting, telephones, electric 
power light and wiring circuits, induction coils, gas engine igniters, 
dynamos and motors, armature windings. By N. H. Schneider. 

ELECTRIC BELLS AND ALARMS. How to install them. By 
N. H. Schneider. Including 'batteries, wire and wiring, circuits, 
pushes, bells, burglar alarms, high and low water alarms, fire alarms, 
thermostats, annnuciators, and the locating and remedying of faults. 
With 56 original diagrams. 

MODERN PRIMARY BATTERIES. Their construction, use 
and maintenance, including batteries for telephones, telegraphs, 
motors, electric lights, induction coils, and for all experimental 
work. By N. H. Schneider. 94 pages, 55 illustrations. The best and 
latest American book on the subiect. 

EXPERIMENTING WITH INDUCTION COILS. H. S. Norrie, 

author of “Induction Coils and Coil Making.” A most instructive 
little book, full of practical and interesting experiments, fully ex¬ 
plained in plain language with numerous hints and suggestions for 
evening entertainments. Arranged under the following headings: 
Introduction; The Handling of Ruhmkorff Coil; Experiments with 
Sparks; Effects in the Vacuum; Induction and Wireless Telegraphy. 
With 36 original illustrations. [In the press] 

SMALL ACCUMULATORS. How made and used, by P. Mar¬ 
shall. Giving full descriptions how to make all the parts, assemble 
them, charge the cells and run them, with examples of their practi¬ 
cal application. Useful receipts and memoranda and a glossary of 
technical terms. 80 pages, 40 illustrations, paper. 

ELECTRIC GAS LIGHTING. How to install Electric gas ignit¬ 
ing apparatus including the jump spark and multiple systems for all 
purposes. Also the care and selection of suitable batteries, wiring 
and repairs, by H. S. Norrie. ioi pages, 57 illustrations, paper 



Price 25c. Each 

MAKING WIRELESS OUTFITS. By Newton Harrison, E.E. 
A concise and simple explanation on the construction and use of 
simple and inexpensive wireless equipments, for sending and re¬ 
ceiving up to 100 miles, giving full details and drawings of apparatus, 
diagrams of circuits and tables. Including the Morse and Con- 
: tinental Codes. 61 pages, 27 illustrations. 

CIRCUITS AND DIAGRAMS. Part 2. By Norman H. 
Schneider. Alternating Current Generators and Motors: Single 
Phase and Polyphase Transformers: Alternating Current and Direct 
Current Motor Starters and Reversers: Arc Generators and Cir¬ 
cuits: Switch-Wiring: Storage Battery: Meter Connections: etc. 
etc. 69 original drawings, with full explanations. 

ALTERNATING CURRENTS SIMPLY EXPLAINED. An Ele- 
! mentary Handbook on Alternating Current Generators, Trans¬ 
formers, and Motors. By Alfred W. Marshall. This book is 
written for those who desire elementary information about Alter- 
, nating electric currents, simply written and yet intensely interest¬ 
ing. Contents of Chapters:—1. What an Alternating Current is. 
2. How Alternating Currents are Produced. 3. How Alternating 
Currents are Measured. 4. Transformers and Choking Coils. 5. 
Alternating Current Motors. 6. Rotary Converters. 7. Rectifiers. 
82 pages, 32 illustrations. 

INDUCTION COILS. How to Make and Use Them, by P. 
Marshall. New edition revised and enlarged by K. Stoye. A 
practical handbook on the construction and use of medical and 
sparking coils for wireless telegraphy, gas engines, automobiles, 
[ gas lighting. X-rays, and all other purposes. With complete 
; tables of windings for coils giving £ in. spark up to 12 in. sparks. 
f With full description for the construction of mercury interrupters, 
i 76 pages, 35 illustrations. 

SIMPLE EXPERIMENTS IN STATIC ELECTRICITY. By P. C. 
Bull, M.A. Contents of Chapters:—1. Production of electricity 
by various means. Viz.: friction, heat, pressure, chemical action, 
etc. 2. Electrical attraction, repulsion, and distribution. 3. 
Induction. 4. Leyden jars and other condensers. 5. Mechanical, 
chemical and. heating effects. 6. Luminous effects. 7. Miscel¬ 
laneous experiments. Being a series of instructive and entertaining 
electrical experiments. 72 pages, 51 illustrations. 

THE MAGNETO TELEPHONE. Its construction, fitting up and 
use, by Norman Hughes. Giving full particulars for planning 
out a short line, putting up the insulators, stringing wires, con¬ 
necting instruments, suitable batteries. 80 pages, 23 illustrations. 

PRACTICAL ELECTRICS. A universal handy book on everyday 
electrical matters, including connections, alarms, batteries, bells, 
carbons, induction and resistance coils, dynamos, measuring, micro¬ 
phones, motors, telephones, phonographs, photophones, etc. 135 
pages, 126 illustrations. 




Price 25c. Each 

WIRELESS TELEPHONE CONSTRUCTION. By Newton 
Harrison. A comprehensive explanation of the making of a 
Wireless Telephone Equipment. Both the transmitting and re¬ 
ceiving stations fully explained with details of construction suffi¬ 
cient to give an intelligent reader a good start in building a Wireless 
Telephone system and in operating it. 74 pages and 43 illustrations. 

THE WIMSHURST MACHINE. HOW TO MAKE AND USE IT. 

A practical handbook on the construction and working of Wimshurst 
machines, including radiography and wireless telegraphy and other 
static electrical apparatus. By A. W. Marshall. Second edition, 
revised and enlarged. Containing a number of sectional drawings 
and details to scale. 112 pages, fully illustrated. 

SMALL ELECTRICAL MEASURING INSTRUMENTS. How to 

Make and Use Them. By Percival Marshall. Contents of 
Chapters:—1. Instruments for testing the presecne of an electric 
current, detectors, galvanometers. 2. Instruments for measuring 
the pressure or quantity of an electric current, amperemeters; 
voltmeters. 3. Instruments for measuring electrical resistance, 
wheatstone bridge. 4. Instruments for measuring static elec¬ 
tricity. 5. Practical details for construction. 6. The principles 
upon which electrical measuring instruments work. 7. How to use 
electrical measuring instruments. 8. How to choose electrical 
measuring instruments. 90 pages, 59 illustrations. 

INVENTIONS. How to Protect, Sell and Buy Them. By 
Frederic B. Wright. Counsellor in Patent Causes. This book 
is especially written for the use of Inventors, instructing them how 
to place their inventions before an Attorney clearly; the rights given 
them under the Law, Patent specifications, Legal forms, and the 
many points necessary for an Inventor to know to protect himself 
under the American Laws. The most practical and clearly written 
American book on this subject, especially intended for the un 
initiated. 114 pages, and 1 sample pattern drawing. 

UNIVERSAL TIME CARD MODEL. By setting to the desired 
hour at any one place the movable model will show at a glance the 
actual time of all the other places in the world. Printed on stiff 
card in two colors, size 7 in. by 9 in. 

HOW TO BUILD A 20 FT. BIPLANE GLIDING MACHINE, 

that will carry a man. By A. P. Morgan. A practical handbook 
on its construction and management. Enabling an intelligent 
reader to make his first step in the field of aviation with a compre¬ 
hensive understanding of some of the principles involved. Fully 
illustrated with detailed drawings. 


25c. BOOKS. 

SMALL DYNAMOS AND MOTORS. How to make and use 
them. A practical handbook, by F. E. Powell. Contents of 
Chapters:—1. General Considerations. 2. Field Magnets. 3 
Armatures. 4. Commutators and Other Details. 5. Tables of 
Windings. 6. How to Build a Small Machine. 7. Useful Data 
8. Testing and Repairing. 76 pages, fully illustrated with detaii 
drawings. 

SMALL ELECTRIC MOTORS. How to make and use them. 
By F. E. Powell. Contents of Chapters:—1. Some points in the 
design of electric motors. 2. Examples of small motors to be 
worked by battery power. 3. A Model four-pole electro motor. 
4. Motors for use on electric lighting circuits. 5. Applications of 
small motors and the power required for certain work. 6. Start¬ 
ing and speed controlling switches; fuses. 7. Reversing switches 
for Model motor; gearing, with tables of windings. 75 pages, 
48 illustrations. 

I ELECTRIC BELLS AND ALARMS. A practical handbook on 
their construction, installation and repair. By F. E. Powell. 
77 pages, 51 illustrations. 

I ELECTRIC BATTERIES. How to make and use them. Prac¬ 
tically describing the common forms of primary batteries. By 
Percival Marshall. 63 pages, 34 illustrations. 

TELEPHONES AND MICROPHONES. A practical handbook 
on their construction and use. By Percival Marshall. In¬ 
cluding testing, faults and their remedies. 80 pages, 33 illustrations. 

SIMPLE ELECTRICAL WORKING MODELS. By Percival 
Marshall. Showing the construction of electrical toys and 
novelties, easily constructed with a few tools from simple materials. 
69 pages, 43 illustrations. 

X-RAYS SIMPLY EXPLAINED. A handbook on the theory 
and practice of Radio-telegraphy. By R. P. Howgrave-Graham. 
A most instructive and interesting work. 93 pages, profusely 
illustrated. 

ELECTRIC LIGHTING FOR AMATEURS. A Practical Guide to 
the installation of light on a small scale, describing the construc¬ 
tion of lamps, lamp-holders, switches, batteries, etc., etc. By 
Percival Marshall. 80 pages, 45 illustrations. 

ELECTRICAL APPARATUS SIMPLY EXPLAINED. A first-rate 

little book describing the principles and working of some of the 
electrical appliances in general use. 80 pages, 35 illustrations. 

SIMPLE SCIENTIFIC EXPERIMENTS. How to perform en¬ 
tertaining and instructive experiments with simple home-made 
apparatus with 59 illustrations. 



25 Cent Books. 


ELECTRIC LIGHTING for amateurs. The installation of elec¬ 
tric light on a small scale, construction of lamps and lamp holders 
switches, batteries and their connections. With 46 illustrations 

SIMPLE ELECTRICAL WORKING MODELS. How to make 
them and how to use them. With 43 illustrations. 

TELEPHONES AND MICROPHONES. Making and using sim¬ 
ple forms of telephones and microphones. With 29 illustrations. 

ELECTRICAL APPARATUS. Simply explained. An introduc¬ 
tory handbook on the principles and working of some of the elec- ; 
trical appliances in general use. 80 pages, 35 illustrations. 

X-RAYS SIMPLY EXPLAINED. The theory and practical ap- j 
plication of Radiography. 10 illustrations and 6 plates. 

STATIC ELECTRICITY. Simple experiments in. A series of 
instructive and entertaining electrical experiments with simple 
and inexpensive apparatus. With 61 illustrations. 

SIMPLE SCIENTIFIC EXPERIMENTS. Howto perform enter- : 
taining and instructive experiments with simple home-made ap¬ 
paratus. By A. DeRatti. 69 pages, 59 illustrations. 25c. 

COOLING TOWERS. Their prominence. Theory. History and 
development. The open type. The forced or fan draft type. The 
natural draft chimney type. Advantages of cooling tower. Econ¬ 
omy and results in cooling; capacity and size. By Oswald Gueth, 
M.E. A very important work of considerable interest to engineers, 
and the designers of steam power plants. With numerous tables, j 
72 pages, 32 illustrations, paper. . 25c.* 

MECHANICAL REFRIGERATION SIMPLY EXPLAINED. Part 

I. Elementary treatise for operating Engineers. Cooling by means 
of expansion and evaporation. The ammonia compression system. 
Operation of the compressor. Refrigeration Plant. The Am¬ 
monia absorption system. Operation. Vogt absorption system. 
Isbel-Portor absorption system. Freezing Mixtures. Advantages 
of the absorption Machine. The Vacuum system. Capacity of 
Ice-Making Machines. Can and plate systems compared. Tables, 
etc., etc. 71 pages, 18 illustrations, paper, 25c. 

PUMP MANUAL FOR ENGINEERS. A practical treatise on 
different kinds of pumps for engineers, including a chapter on De¬ 
signing Pumps, by R. H. Brooks. Pumping machinery for Acid 
Water by Kresse. Hydrant and Hose Pipe Data, Installation of 
Pumps in Power Plants. With numerous tables, illustrations, notes 
and useful infonnatioi*. 







25c. BOOKS. 

THE BEGINNERS GUIDE TO THE LATHE. An elementary 
instruction book on turning in wood and metal. By Percival 
Marshall. Specially written in plain language for the beginner 
and as an elementary text-book for manual training schools. Con¬ 
tents of Chapters:—1. The lathe and its parts. 2. Method of 
holding and driving work. 3. Turning in wood. 4. Turning in 
metal. 5. The Slide-Rest. 6. Drilling and boring in the lathe. 
76 pages, 75 illustrations. 

MECHANICAL DRAWING SIMPLY EXPLAINED. By F. E. 

Powell. The threefold object of this book is to show how draw¬ 
ings are made, how to read other peoples’ drawings, and how to 
make practical working drawings. Contents of Chapters:—1. 
Introduction. 2. The use and care of drawing instruments. 3. 
On 44 reading ” and setting out drawings. 4. Inking-in and finish¬ 
ing drawings. 5. On drawing for reproduction. 78 pages, 44 
illustrations. 

MODEL STEAMER BUILDING. By Percival Marshall. A 
practical handbook on the design and construction of model steamer 
hulls, deck-fittings, and other details, including a model torpedo 
boat destroyer, and a side-wheel passenger steamer. With laying- 
off tables. 64 pages, 39 illustrations. 

MACHINERY FOR MODEL STEAMERS. By Percival Mar¬ 
shall. A practical handbook on the design and construction of 
engines and boilers for model steamers, single and double cylinder 
engines, side wheel engines. The use of liquid, fuel, and the pro¬ 
portions of machinery for model boats. 64 pages, 44 illustrations. 

SIMPLE MECHANICAL WORKING MODELS. How to make 
and use them. By Percival Marshall. How to make the 
following: Water and wind motors; hot-air engines; steam en¬ 
gine and pump; slide valve launch engine; model steam boats; 
working locomotive in cardboard, model gravitation railway, etc. 
64 pages, 34 illustrations. 

MODEL STEAM ENGINES. How to Understand Them and How 
to Run Them. By H. Greenly. Including examples of stationary 
locomotive, portable and marine engines. With different kinds 
of boilers and methods of getting up steam, as well as engine de¬ 
tails and valve mechanisms, etc. 87 pages and 55 illustrations. 

MODEL STEAM ENGINE DESIGN. A handbook for the De¬ 
signer of small Model Steam Engines, including original tables and 
calculations for speed, power, proportions of pumps, compound 
engines, and valve diagrams. By Robert M. de Vignier. Con¬ 
tents of Chapters: 1. Various Types. Speed of Model Engines. 
2. Power Calculations. Materials. 3. Feed Pumps. 4. Com¬ 
pound Engines. 5. The Valve Diagram. 6. Engine Layout. Pat¬ 
terns. 102 pages, 34 illustrations. 


25c. BOOKS, 


WOODWORK JOINTS. How to make and wnere to use them. 
A new revised and enlarged edition. Contents of Chapters: 1. 
Mortise and tenon joints. 2. Lap joints. 3. Dove-tail joints. 4. 
“ Glue ” joints. 5. Scarfing joints and joints for lengthening 
timbers. 6. Circular work, showing how to make joined woodwork 
frames in the form of ovals and circles. The work describes clearly 
the construction of the principle joints used in carpentry and 
joinery, and shows not only how to set them out, but indicates for 
what purpose they are best suited. 101 pages, 178 illustrations. 

THE LOCOMOTIVE, simply explained. By Chas. S. Lake. 
A first introduction to the study of the locomotive engine, their 
designs, construction and erection, with a short catechism in the 
form of questions and answers. 72 pages, 26 illustrations. 


STANDARD SCREW THREADS AND TWIST DRILLS. A 

Guide to. By George Gentry. The tables given are for small 
sizes of the following makers:—Whitworth Standard; British 
association standard; bicycle screw threads; cycle standard; V 
Standard and U. S. Standard forms; International standard thread, 
metric system; “ Progress ” metric system of screws for watches; 
77 pages, 6 illustrations. 


SIMPLE CHEMICAL EXPERIMENTS. A series of instructive 
experiments in inorganic chemistry. By T. T. Baker. Contents 
of Chapters:—1. How to fit up and equip a small chemical labora¬ 
tory. 2. How to fit up apparatus. 3. Elements and compounds. 
4. Preparation of Chlorine. Ammonia, hydrochloric acid, etc. 5. 
Combustion. 6. How to make oxygen; hydrogen; ozone; etc. 7. 
Preparation of metallic salts. 8. Sulphur. 9. The atmosphere. 
10. Making Chemicals. 72 pages, 19 illustrations. 


THE MODEL VAUDEVILLE THEATRE. By Norman H. 

Schneider. Describing the construction of a model theatre and the 
making of numerous devices to be used with it. With suggestions 
for various novelties for an evenings’ entertainment, including i 
chapters on shadowgraphs, the use of a polyopticon, lighting effects, ! 
wave effects, storms, etc. etc. One of these small theatres can be j 
made very easily and at small expense and will afford many hours | 
of amusement not only to the young but also to the grown-up, 1 
as there is no limit to the scope of the entertainments that can be : 
produced thereon, fully illustrated. 

SIMPLE SOLDERING BOTH HARD AND SOFT. Together with 
a description of inexpensive home-made apparatus. By Edward i 
Thatcher, Instructor of Manual Training, Teachers’ College, Col- j 
umbia University.* 



EDUCATIONAL WOODWORK. By A. C. Horth. A complete 
manual for teachers and organizers of woodworking classes. Con¬ 
tents: 1. First Year Course. 2 . Second Year Course. 3. Third 
Year Course. 4. Fittings and Furniture. 5. Discipline. 6 . Organ¬ 
ization and Method. 7. The Instruction of the Physically and 
Mentally Deficient and Blind. 8. Object Lessons. Fully illus¬ 
trated with photographs, drawings and facsimile blackboard les¬ 
sons. 159 pages, 12mo., cloth. $1.00. f 

THE BEGINNER’S GUIDE TO CARPENTRY. A practical hand¬ 
book for Amateurs and Apprentices. By Henry Jarvis. Con¬ 
tents of Chapters: 1. Indispensable Tools. 2. How to Use the Saw. 

3. How to Use the Plane. 4 . How to Use Chisels and Gouges. 
5. How to Use the Spokeshave, Axe, Pincers, Compasses, Gimlets, 
Brad-awls, Hammer, etc. 6. Making the Bench. 7 . Timber: 
How Sold, etc. 8. Additional Tools and How to Use Them. 9 . 
Sharpening Tools. 10 . Home-made Tools and Appliances. 11. 
Facing up and Setting out Work. 12 . On Setting out and Putting 
Together Work Joining at Other than Right Angles. 13 . Glue: 
How to Purchase, Prepare, and Use. 14 . How to Make Joints: 
Use of the Plough, etc. 15 . Ornamenting Work, Curved Work, 
Scribing, etc. 128 pages, 99 illustrations, 12mo., boards. 60c.* 

MODEL SAILING YACHTS. How to Build, Rig. and Sail Them. 
A practical handbook for Model Yachtsmen. Edited by Percival 
Marshall. Contents of Chapters: 1. Introductory: Types of 
Yachts and Rigs: How to Choose a Model Yacht. 2. The Rating 
of Model Yachts. 3 . The Construction of “ Dug-Out ” Yachts. 

4 . The Construction of “ Built-Up ” Yachts. 5 . Sails and Sail 
Making. 6. Spars and Fittings. 7 . Rudders and Steering Gears. 
8. Notes on Sailing. 144 pages, 107 illustrations, 12mo., boards. 
60c.* 

WOODWORK JOINTS. How to make and where to use them; 
including mortise and tenon joints, lap joints, dovetail joints, 
glue joints and scarfing joints. With a chapter on Circular Wood¬ 
work, revised and enlarged edition. A practical guide for wood¬ 
workers. 101 pages, 178 illustrations. 25c. 

THE BEGINNER’S GUIDE TO FRETWORK. Containing full 
instructions on the Use of Tools and Materials; and six full size 
fretwork designs. With 39 pages and 26 illustrations. 25c. 

VENEERING, MARQUETRY AND INLAY. A practical instruc¬ 
tion book in the art of Decorating Woodwork by these Methods. 
By P. A. Wells. 79 pages, 37 illustrations. 25c. 

SOFT WOODS AND COLONIAL TIMBERS. The selection and 
uses of soft woods and colonial timbers. The cultivation, cutting 
and seasoning. By P. A. Wells. 57 pages, 15 illustrations. 25c. 

HARD WOODS, ENGLISH AND FOREIGN. A practical de¬ 
scription of hard and fancy woods used by the carpenter and 
cabinet maker. By P. A. Wells. 79 pages, 19 illustrations. 26c. 





SCONS’ 


]YJecI}aijics ()\Vi]^^°°k 

A WORK THAT SHOULD BE IN YOUR BOOKCASE. 


The general method of treatment of each subject, is first 
the raw materials worked upon, its characteristics, variations 
and suitability; secondly, the tools used, the sharpening 
and use; thirdly, devoted to typical examples of work to be 
done, materials, and how to do similar work, etc* 

THE FOLLOWING ARE THE PRINCIPAL CONTENTS. 

Mechanical Drawing, (13 pages.) 

Mechanical Movements, (55 pages.) 

Casting and Founding in Brass and Bronze, (30 pages.) 

Forging and Finishing, (46 pages.) 

Soldering in all its branches, (26 pages.) 

Sheet Metal Working, (10 pages.) 

Turning and Turning Lathes, (31 pages.) 

Carpentry, (224 pages.) 

Log Huts, Building, Etc., (8 pages.) 

Cabinet-Making, (36 pages.) Upholstery, (6 pages.) 

Caning and Fretwork, (13 pages.) 

Picture Frame Making, (4 pages.) 

Printing, Graining and Marbling, (28 pages.) 

Staining, (13 pages.) Gilding, (3 pages.) 

Polishing, (23 pages.) Varnishing, (4 pages.) 

Paper Hanging, (4 pages.) Glazing, (7 pages.) 

Plastering and White Washing, (9 pages.) 

Lighting, (8 pages.) 

Foundations and Masonry, (46 pages.) 

Roofing, (14 pages.) 

Ventilating and Warming, (13 pages.) 

Electric Bell and Bell Hanging, Gas Fitting, ^8 pages.) 

Roads and Bridges, Banks, Hedges, Ditches and Drains, 
phalt Cement Floors, Water Supply and Sanitation. 

ITotal number of pages 702. Total number illustrations 1,420 

Bound in substantial half-extra, - PRICE BY MAIL ONLY $2.50 

We have an 8 page circular giving lull contents which will be seal 
Idee oo application* 




50 Cent Books 


PRACTICAL DYNAMO AMD MOTOR CONSTRUCTION. A hand¬ 
book of Constructive Details and Workshop Methods used in 
Building Small Machines. By Alfred W. Marshall. Contents 
of Chapters: 1. Field Magnets. 2. Winding Field Magnets. 3. 
Drum Armature Building. 4. Ring Armature Building. 5. How 
to Wind Armatures. General Notes. Siemens or H Armatures. 
Polar Armatures. 6. How to Wind Armatures (continued). Drum 
and Ring Armatures. Binding Wires and Repairs. 7. Commutator 
Making. 8. Brush Gears. 9. Mechanical Details of Dynamos and 
Motors. 10. Terminals and Connections. 131 pages, 133 illustra¬ 
tions, 12mo., boards. 

MODEL SAILING YACHTS. How to Build, Rig, and Sail Them. 
A practical handbook for Model Yachtsmen. Edited by Percival 
Marshall. Contents of Chapters: 1. Introductory: Types of 
Yachts and Rigs: How to Choose a Model Yacht. 2. The Rating 
of Model Yachts. 3. The Construction of “ Dug-Out ” Yachts. 

4. The Construction of “ Built-Up ” Yachts. 5. Sails and Sail 
Making. 6. Spars and Fittings. 7. Rudders and Steering Gears. 
8. Notes on Sailing. 144 pages, 107 illustrations, 12mo., boards. 

PRACTICAL MOTOR CAR REPAIRING. A handbook tor Motor 
Car Owners and Drivers. By Eric W. Walford. Contents of 
Chapters: 1. The Motor. 2. Ignition. 3. Cooling System. 4. The 
Carburettor: Exhaust and Lubrication Systems. 5. Transmission. 
6. Frames, Springs, Axles and Wheels. 7. Tires. 8. Causes and 
Effects. 9. Miscellaneous. 126 pages, 39 illustrations, 12mo., 
boards. 

THE BEGINNER’S GUIDE TO CARPENTRY. A practical hand¬ 
book for Amateurs and Apprentices. By Henry Jarvis. Con¬ 
tents of Chapters: 1. Indispensable Tools. 2. How to Use the Saw. 
3. How to Use the Plane. 4. How to Use Chisels and Gouges. 

5. How to Use the Spokeshave, Axe, Pincers, Compasses, Gimlets, 
Brad-Awls, Hammer, etc. 6. Making the Bench. 7. Timber: 
How Sold, etc. 8. Additional Tools and How to Use Them. 9. 
Sharpening Tools. 10. Home-made Tools and Appliances. 11. 
Facing up and Setting out Work. 12. On Setting out and Putting 
Together Work Joining at Other than Right Angles. 13. Glue: 
How to Purchase, Prepare, and Use. 14. How to Make Joints: 
Use of the Plough, etc. 15. Ornamenting Work, Curved Work, 
Scribing, etc. 128 pages, 99 illustrations, 12mo., boards. 

CIRCULAR SLIDE RULE. The Use and Working of the Watch 
Calculator and Circular Slide Rule. Contents of Chapters: 1. 
The Watch Form of Calculator. 2. The Gravet Slide Rule. 3. The 
Theory of the Slide Rule and Calculator. With 10 folding plates 
of illustrations. 12mo., limp cloth. 



PRACTICAL DYNAMO AND MOTOR CONSTRUCTION. A 

handbook of Constructive Details and Workshop Methods used in 
Building Small Machines. By Alfred W. Marshall. Contents 
of Chapters: 1 . Field Magnets. 2 . Winding Field Magnets. 3 . 
Drum Armature Building. 4 . Ring Armature Building 5 . How 
to Wind Armatures. General Notes. Siemens or H Armatures. 
Polar Armatures. 6. How to Wind Armatures (continued). Drum 
and Ring Armatures. Binding Wires and Repairs. 7 . Commutator 
Making. 8. Brush Gears. 9 . Mechanical Details of Dynamos and 
Motors. 10. Terminals and Connections. 131 pages, 133 illustra¬ 
tions, 12mo., boards. 50 c.* 

SMALL ACCUMULATORS. How made and used. An elementary 

handbook for the use of amateurs and students. By Percival i 
Marshall, A.I.M.E. Contents of Chapters: 1 . The Theory of the 
Accumulator. 2 . How to Make a 4 -Volt Pocket Accumulator. 

3 . How to Make a 32 -Ampere Hour Accumulator. 4 . Types of 
Small Accumulators. 5 . How to Charge and Use Accumulators. 

6 . Applications of Small Accumulators, Electrical Novelties, etc. | 
Glossary of Technical Terms. 80 pages. 40 illustrations. 12mo., 
cloth. 50 c. 

THE MAGNETO-TELEPHONE. Its construction, fitting up and | 

adaptability to everyday use. By Norman Hughes. Contents of 
Chapters: Some Electrical Considerations: 1 . Introductory. 2 . 
Construction. 3 . Lines, Indoor Lines. 4 . Signaling Apparatus. 

5 . Batteries. Open Circuit Batteries. Closed Circuit Batteries. 

6 . Practical Operations. Circuit with Magneto Bells and Lightning 
Arresters. How to Test the Line. Push-Button Magneto Circuit. 
Two Stations with Battery Bells. 7 . Battery Telephone. Battery 
Telephone Circuit. Three Instruments on one Line. 8. General 
Remarks. Index. 80 pages, 23 illustrations, 12mo., cloth. 50c. 

ELECTRIC GAS LIGHTING. How to install electric gas igniting 

apparatus, including the jump spark and multiple system for use in 
houses, churches, theatres, halls, schools, stores or any large building. 
Also the care and selection of suitable Batteries, Wiring and Re¬ 
pairs. By H. S. Norrie (author of Induction Coils and Coil Mak¬ 
ing). Contents of Chapters: 1 . Introduction. Means of Producing 
Sparks, Induction, Induction Coils. 2 . Application of Induction 
Coils to Gas Lighting. Forms of Burners used, Pendant, Rachet, 
Stem, Welsbach, Automatic Burners for Gasolene and Acetylene. 

3 . How to Connect up Apparatus. Wiring a House. Locating 
Breaks or Short Circuits. Wiring in finished Houses. General 
Remarks. 4 . Primary Coils and Safe Devices. 5 . How to Wire 
and Fit up Different Systems for Lightning Large Buildings. 6. The 
Selection of Suitable Batteries for Gas Lighting, Repairs, Main¬ 
tenance, etc. 108 pages, 57 illustrations and diagrams, cloth. 50c. 


Induction .*. Coils 

How to Make aod Use Them 

INCLUDING RUHMKORFF, TESLA AND MEDICAL COILS 
COILS FOR WIRELESS TELEGRAPHY 
AND X=RAY WORK. 

Spark Coils for Gas Engines, Electric Gas Lighting, &c., &c. 

By H. S. NORRIE. 

This work has been so well received that it has now reached the Fourth 

Edition ( 1907 .) 


Considerable space in the new matter is given to the following: 
Medical and bath coils, gas engine and spark coils, contact breakers, 
primary and secondary batteries; electric gas lighting; new method 
of X-ray work, etc. A complete chapter on wireless telegraphy; 
a number of new tables and 25 new and original illustrations. 
Great care has been given to the revision to make this book the 
best American work on the subject. A very complete index, con¬ 
tents, list of illustrations and contents of tables have been added. 

CONTENTS OF CHAPTERS. 

1. Construction of coils; sizes of wire; winding; testing; insula¬ 
tion; general remarks; medical and spark coils. 2. Contact breakers. 
3. Insulation and cements. 4. Construction of condensers. 5. Ex¬ 
periments. 6. Spectrum analysis. 7. Currents in vacuo; air pumps. 
8 . Rotating effects. 9. Electric gas lighting; in multiple; in series. 
10. Primary batteries for coils; varieties; open circuit cells; closed 
circuit cells; solutions. 11. Storage or secondary batteries; construc¬ 
tion; setting up; charging. 12. Tesla and Hertz effects. 13. Roent¬ 
gen Radiography. 14. Wireless telegraphy; arrangement of circuits 
of coil and coherer for sending and receiving messages; coherers; 
translating devices; air conductors; tables; contents; index. 

XII+ 269 pages, 78 illustrations, 5x6^ inches, cloth, $1.00. 



WIRELESS TELEGRAPHY FOR AMATEURS A handbook on 

the Principles of Radiotelegraphy and the construction and work¬ 
ing of apparatus for short Distance Transmission. By R. P. How- 
grave-Graham. This is a most important new work for the am¬ 
ateur who wishes to make apparatus that are not mere toys. 
While the author gives all the technical information that is neces¬ 
sary, the best part of the book is devoted to practical details, 
construction and operation, making the book one of the most 
valuable on this subject. Contents of Chapters: Preface. 1. 
History and Principles of Radio-Telegraphy. 2. The Poulsen 
System of Generating Electric Waves for Radiotelegraphy. 3. 
Practical Radiotelegraphy, Transmitting Apparatus. 4. Re¬ 
ceiving Apparatus. Appendix. 160 pages, 51 illustrations, 12mo., 
cloth. $1,004 


THE A B C OF THE TELEPHONE By J. E. Homans. While 

this work is strictly elementary in the sense that it begins with 
the elements it nevertheless gives a very comprehensive survey 
of the entire field of telephone apparatus and construction in¬ 
cluding an excellent chapter on the theory of sound and another 
on the fundamental principles of electricity. Written in plain 
language it is a book that can be recommended. The work is 
divided into 29 chapters and contains 375 pages, 268 illustrations 


and diagrams, 12mo., cloth. $1.00.* 


PRIVATE HOUSE ELECTRIC LIGHTING. A popular handbook 

of modem methods in wiring and fitting as applied to private 
houses, including a chapter on small generating plants. By F. H. 
Taylor. 2d edition, rewritten. Contents of Chapters: 1. Systems 
of Supply. 2. Systems of Wiring. 3. Arrangements of Circuits 
and Conductors, etc. 4. Arrangements of Lights and Switches. 
5. The Testing of an Installation. 6. The Materials and Accessories 
Used. 7. Cost of Installation Work. 8. Cost of Using Electric 
Light. 9. Generating Plant. 132 pages, 66 illustrations, 12mo., 
boards. 50c * 


GROUPING OF ELECTRIC CELLS. A treatise on. By F. W. 

Dunton. Treating of the numerous forms and grouping of electric 
cells for convenience, economy, efficiency and other reasons. 
Part I.—The Grouping of Similar Cells for Greatest Current. 
Introductory. Regular Groups. Irregular Points and General 
Rule. Part II.—The Economical of Similar Cells. The Shortest 
Group. The Smallest Group. Index, with numerous formulas. 
60 pages, 16mo., cloth. 60c.J 

PRACTICAL ELECTRICS. A universal handbook on everyday 

electrical matters, electric burglar and other alarms, different kinds 
of primary and secondary batteries, electric bells and annunciator 
system, carbons, connections, induction coils, resistance and in¬ 
tensity coils, dynamo-electric machines, magneto dynamos, con¬ 
struction, fire-risks, wires, lamps, measuring instruments, con¬ 
struction of microphones, phonographs; and photophones; motors; 
storage batteries; telephones; circuits and calls, etc., ^135 pages, 
126 illustrations, 8vo., cloth. 76c. 


ELECTR 



MINTS 


AND TEST1 


How to Use the Voltmeter, Ammeter, Galvanometer, Potentiometer, Ohmmeter, 
the Wheatstone Bridge, and the Standard Portable Testing Sets. 

BY NORMAN H. SCHNEIDER. 

THIRD EDITION WITH NEW CHAPTERS ON 

Testing Wires and ©isles and Locating Failts 

In Telegraph and Telephone Systems. 

BY JESSE HARGRAVE, 

Assistant Electrical Engineer, Postal Telegraph Cable Co. 


The fact that two editions of this book have already been sold 
proves the utility of this work. The publishers, however, deter¬ 
mined to make it still more complete and up to date by adding 
additional chapters especially for telephone and telegraph wire 
men. The new information was prepared by an authority. 

The first chapters of the work describe the various forms of 
electrical testing and measuring instruments and their construction. 

The balance of the work is devoted to practical measuring and 
testing, using the different instruments described and including 
tests for insulation, resistance, current and e.m.f. made with a 
voltmeter, as well as many telephone and telegraph tests. 

In working out the many practical examples simple algebraic 
formulas only are; used and these are fully explained in plain lan¬ 
guage. Most of the diagrams have been specially drawn for this 
book. The work is divided into XIII chapters as follows: 

Introduction. Chapters I and II, The Galvanometer. Ill, 
Rheostats. IV, The Voltmeter. V, The Wheatstone Bridge. VI, 
Forms of Portable Sets. VII, Current Flow and e.m.f. VIII, The 
Potentiometer. IX, Condensers, X, Cable Testing. XI, Testing 
with Voltmeter. XII, Testing Telegraph Wires and Cables. XIII, 
Locating Faults in Telegraph and Telephone Wires and Cables. 

Tables. Index. 

256 pages, 133 illustrations and diagrams, 12mo., cloth, $1.00f 
Full limp leather, $2.00 .t 










PRINCIPLES OF 


ELECTRICAL POWER. 

(CONTINUOUS CURRENT.) 

FOR MECHANICAL ENGINEERS* 


BY 

A. H. BATE, A.M.I.E.E. 


The rapid progress that has been made of late years in the appli¬ 
cation of electricity to industrial purposes, and particularly in the 
transmission of power by means of the electric motor, has made it 
imperative for every engineer who wishes to keep up to date to 
have some knowledge of the way electrical currents are controlled 
and used for practical purposes. This work is especially written 
for the practical engineer, mathematics being avoided. 

Contents of Chapters. 

1. The Electric Motor. 

2. Magnetic Principles. 

3. Electrical Measurements. 

4. The Dynamo. 

5. Construction of Motor. 

6. Governing of Motors. 

7. Open and Closed Motors; rating. 

8. Motor Starting Switches. 

9. Speed Control of Shunt-wound Motors. 

10. Series Motor Control. 

11. Distribution System. 

12. Installing and Connections. 

13. Care of Dynamos and Motors. 

14. Cost of Plant. 

15. Examples of Electric Driving. 

Horse-power absorbed by various machines, including general 
engineering and shipyard machines; wood working and printing 
machinery (arranged in 14 pages of tables). 

XII+ 204 pages, 63 illustrations, 12 mo. cloth. $2.00 * 





THE PRACTICAL ENGINEER’S HANDBOOK. 
TO THE CARE AND MANAGEMENT OF 


F.LECTRIC P OWER P LANTS 

By NORMAN H. SCHNEIDER, 

Chief Engineer , 44 White City,” Coling'wood, Ohio. 


EXTRACTS FROM PREFACE. 

In revising the first edition of Power Plants the author decided 
to greatly enlarge it in the hope that it will have a still greater 
success than the first one. The section on theory is thoroughly 
revised. A complete chapter on Standard Wiring including new 
tables and original diagrams added. The National Fire Under¬ 
writers’ rules condensed and simple explanations given. 

Direct and alternating current motors have been given a special 
chapter and modern forms of starting rheostats described at length. 
The principles of alternators have been considered also trans¬ 
formers and their applications. Modern testing instruments and 
their use are given a separate chapter. New matter has been 
added to storage batteries including charging of automobile bat¬ 
teries, 10 new tables, and 137 new illustrations. 

SYNOPSIS OF CONTENTS OF CHAPTERS. 

1. The Electric Current; series and multiple connections; 
resistance of circuits; general explanation of formulas. 

2. Standard Wiring; wiring formulas and tables; wiring sys¬ 
tems; cut-outs; conduits; panel boxes; correct methods of wiring. 

3. Direct and Alternating Current Generators; manage¬ 
ment in the power house; windings; selection of generators. 

4. Motors and Motor Starters; various forms of motors; con¬ 
trollers; care of motors and their diseases; rules for installing. 

5. Testing and Measuring Instruments; voltmeter testing 
and connections; instruments used; switchboard instruments. 

6. The Storage Battery; different kinds; switchboards for 
charging fixed and movable batteries; management of battery. 

7. The Incandescent Lamp; various methods of testing; life 
of lamps. 

8. Engineering Notes; belts and pulleys h.p. of belts. Tables 
Contents. Index. 

290 pages, 203 illustrations. 12mo., cloth, $1.50, 

Full limp leather, $2.50 













Design of Dynamos 

BY 

SILVANUS P. THOMPSON, D. Sc., B. A., F. R* S. 

EXTRACTS FROM PREFACE. 

“ The present work is purposely confined to continuous current 
'generators. The calculations and data being expressed in inch 
measures; but the author has adopted throughout the decimal sub¬ 
division of the inch; small lengths being in mils, and small areas of 
cross-section in sq. mils, or, sometimes, also, in circular mils.” 

CONTENTS OF CHAPTERS. 

1. Dynamo Design as an Art. 

2. Magnetic Data and Calculations. Causes of waste of 
Power. Coefficients of Dispersion. Calculation of Dispersion. 
Determination of exciting ampere-turns. Example of Calculation. 

3. Copper Calculations. Weight of Copper Wire. Electrical 
resistance of Copper, in cube, strip, rods, etc. Space-factors. Coil 
Windings; Ends; Insulation; Ventilating; Heating. 

4. Insulating Materials and Their Properties. A list of 
materials, including “ Armalac,” “ Vitrite,” “ Petrifite,” “ Mican- 
ite,” “ Vulcabeston,” “ Stabilite,” “Megohmite,” etc. With tables. 

5. Armature Winding Schemes. Lap Windings, Ring Wind¬ 
ings, Wave Windings, Series Ring-Windings, Winding Formulae. 
Number of circuits. Equalizing connections. Colored plates. 

6. Estimation of Losses, Heating and Pressure-drop. Cop¬ 
per Losses, Iron Losses, Excitation Losses, Commutator Losses, 
Losses through sparking. Friction and Windage Losses. Second¬ 
ary Copper Losses. 

7. The Design of Continuous Current Dynamos. Working 
Constants and Trial Values; Flux-densities; Length of Air-gap; 
Number of Poles; Current Densities; Number of Armature Con¬ 
ductors; Number of Commutator Segments; Size of Armature 
(Steinmetz coefficient); Assignment of Losses of Energy; Cen¬ 
trifugal Forces; Calculation of Binding Wires; Other procedure in 
design. Criteria of a good design. Specific utilization of material. 

8. Examples of Dynamo Design. 

1. Shunt-wound multipolar machine, with slotted drum arma¬ 
ture. 2. Over-compounded Multipolar traction generator, with 
slotted drum armature, with general specifications, tables, dimen¬ 
sions and drawings, fully described. 

A number of examples of generators are given in each chapter, 
fully worked out with rules, tables and data. 

VIII.X253 pages, 92 illustrations, 10 large foiling plates and 4. 

Three-color Plates, 8vo., cloth, $3.50. 



ynamo=Electric Machinery 

VOL* L—CONTINUOUS CURRENT. 


BY 

SILVANUS P. THOMPSON, D.Sc.,B.A.,F.R.S* 


7th Edition Revised and Greatly Enlarged. 


CONTENTS OF CHAPTERS."" 

I. Introductory. 2. Historical Notes. 

3. Physical Theory of Dynamo-Electric Machines. 

4. Magnetic Principles; and the Magnetic Properties of Iron. 

5. Forms of Field-Magnets. 

6. Magnetic Calculations as Applied to Dynamo Machines. 

7. Copper Calculations; Coil Windings. 

8. Insulating Materials and their Properties. 

9. Actions and Reactions in the Armature. 

10. Commutation; Conditions of Suppression of Sparking. 

II. Elementary Theory of the Dynamo, Magneto and Separately) 
Excited Machines, Self-exciting Machines. 

12. Characteristic Curves. 

13. The Theory of Armature Winding. 

14. Armature Construction. 

15. Mechanical Points in Design and Construction. 

16. Commutators, Brushes and Brush-Holders. 

17. Losses, Heating and Pressure-Drop. 

18. The Design of Continuous Current Dynamos. 

19. Analysis of Dynamo Design. 

20. Examples of Modern Dynamos (Lighting and Traction). 

21. Dynamos for Electro-Metallurgy and Electro-Plating. 

22. Arc-Lighting Dynamos and Rectifiers. 

23. Special Types of Dynamos; Extra High Voltage Machines, 
Steam-Turbine Machines, Extra Low Speed Machines, Exciters, 
Double-Current Machines, Three-Wire Machines, Homopolar (Uni¬ 
polar) Machines, Disk Dynamos. 

24. Motor-Generators and Boosters. 

25. Continuous-Current Motors. 

26. Regulators, Rheostats, Controllers and Starter. 

27. Management and Testing of Dynamos. 

Appendix, Wire Gauge Tables. Index. 

996 pages, 573 illustrations, 4 colored plates, 32 large folding 
plates. 8vo.. cloth. $7.50.1 









Alternating - Current Machinery 

BEING VOL. II OF 

Dynamo-Electric Machinery. 

by 

SILVANUS P, THOMPSON, D.Sc, B.A., F.R.S. 


Owing to the enormous increase in the use of electrical machinery ! 
since the publication of the sixth edition of Dynamo-Electric ; 
Machinery the author has deemed it advisable to divide the work. 
Vol. I. is devoted to Direct Current Machinery and this the 
second part. Vol. II. Alternating Current Machinery. | 
Amongst the many new features treated special mention must be ] 
made of the number of fine colored plates of windings and the many ! 
large folding scale drawings. These two volumes make the most 
comprehensive and authoritative work on dynamo machinery. | 
The work has been so universally adopted that it has been found 
necessary to translate it into French and German. 

CONTENTS OF CHAPTERS. 

1. Principles of Alternating Currents. 

2. Periodic Functions. 

3. Alternators. 

4. Induced E.M.F. and Wave-Forms of Alternators. 

5. Magnetic Leakage and Armature Reaction. 

6. Winding Schemes for Alternators. 

7. Design of Alternators. Compounding of Alternators. 

8. Examples of Modern Alternators. 

9. Steam Turbine Alternators. 

10. Synchronous Motors, Motor Generators, Converters. 

11. Parallel Running of Alternators. 

12. Transformers. 13. Design of Transformers. 

14. Induction Motors. 15. Design of Induction Motors. 

16. Examples of Induction Motors. 

17. Single-Phase Induction Motors. 

18. Alternating-Current Commutator Motors. 

Appendix. The Standardization of Voltages and Frequencies. 

Complete Index. 

XX+ 848 pages, 546 illustrations, 15 colored plates and 24 large 
folding plates. 8vo., cloth. $7.50| 




Books for Steam Engineers 


DIGRAM OF CORLISS ENGINE. A large engraving giving 
a longitudinal section of the Corliss engine cylinder, showing rela¬ 
tive positions of the piston, steam valves, exhaust valves, and 
wrist plates when cut-off takes place at % stroke for each 15 degrees 
of the circle. With full particulars. Reach-rods and rock shafts. 
The circle explained. Wrist-plates and eccentrics. Explanation of 
figures, etc. Printed on heavy paper, size 13 in. x 19 in., 25c. 

THE CORLISS ENGINE and its Management. A Practical 
Handbook for young engineers and firemen, ( 3 rd edition) by J. T. 
Henthorn. A good little book, containing much useful and practi¬ 
cal information. Illustrated, cloth, $ 1 .00. 

THE FIREMAN’S GUIDE to the Care and Management of 
Boilers, by Karl P. Dahlstrom, M. E., covering the following sub¬ 
jects: Firing and Economy of Fuel; Feed and Water Line: Low 
Water and Priming: Steam Pressure: Cleaning and Blowing Out; 
General Directions. A thoroughly practical book. Cloth, 50c. 

ABC OF THE STEAM ENGINE. With a description of the 
automatic shaft governor, with six large scale drawings. A prac¬ 
tical handbook for firemen helpers and young engineers, giving a 
set of detail drawings all numbered and lettered and with names 
and particulars of all parts of an up-to-date American high speed 
stationary steam engine. Also a large drawing and full descrip¬ 
tion of the automatic shaft governor. With notes and practical 
hints. This work will prove of great help to all young men who 
wish to obtain their engineer’s license. Cloth, price 50c. 

HOW TO RUN ENGINES AND BOILERS. By E. P. Watson, 

(for many years a practical engineer, and a well-known writer in The 
Engineer .) A first-rate book for beginners, firemen and helpers. 
Commencing from the beginning, showing how to thoroughly overhaul 
a plant, foundations, lining up machinery, setting valves, vacuum, 
eccentrics, connection, bearings, fittings, cleaning boilers, water tube 
boilers, running a plant, and many useful rules, hints and other 
practical information; many thousands already sold. 160 pages, 
fully illustrated, cloth, $ 1 . 00 . 

AMMONIA REFRIGERATION. By I. I. Redwood. A practi¬ 
cal work of reference for engineers and others employed in the man¬ 
agement of ice and refrigerating machinery. A first-rate book, be¬ 
ginning from the bottom and going carefully through the various 
processes, stage by stage, with many tables and original illustrations. 
Cloth, $1.00. 

MEYER SLIDE VALVE. Position diagram of cylinder with 
cutoff at 1 ^, % and ^ stroke of piston with movable valves, on 
card 7 %in. x 5 % in. Price, 25c« 



25c. BOOKS. 

THE SLIDE VALVE SIMPLY EXPLAINED. A practical treatise 

for locomotive engineers by W. J. Tennant, revised and enlarged 
by J. H. Kinealy. Contents of Chapters:—Introduction. 1. 
The simple slide. 2. The eccentric, a crank. Special model to 
give quantitative results. 3. Advance of the eccentric. 4. Dead 
center. Order of cranks. Cushioning and lead. 5. Expansion— 
lap and lead; advance, compression. 6. Double ported and piston 
valves. 7. The effect of alterations to valve, and eccentric. 8. 
Notes on link motions. 9. Cut-offs, reversing gears, etc. 89 pages, 
41 illustrations. 

MANAGEMENT OF BOILERS. The Fireman’s Guide. A 
Handbook on the Care of boilers. By K. P. Dahlstrom. Espec¬ 
ially written in plain English for the use of beginners and firemen. 
Contents of Chapters:—Introduction. 1. Firing and Economy 
of fuel. 2. Feed and Water-line. 3. Low water and foaming or 
priming. 4. Steam-pressure. 5. Cleaning and Blowing out. 6. 
General directions. Summary of rules. 

INJECTORS. THEIR CONSTRUCTION, CARE AND MANAGE¬ 
MENT. By Frederick Keppy. Second edition. The best and most 
practical treatise on this subject as it is written by a practical 
engineer for the instruction of engineers. 69 pages, 45 illustrations, 
price 25c. 

REFRIGERATION AND ICE-MAKING. By W. H. Wakeman. 

Fourth edition. Consisting of practical notes and information for 
engineers. 43 pages, tables and illustrations, price 25c. 

STEAM TURBINES. How to design and build them. By 
H. H. Harrison. A practical handbook for model makers. Con¬ 
tents of Chapters. 1. General Consideration. 2. Pressure De¬ 
veloped by an Impinging Jet; Velocity and Flow of Steam Through 
Orifices. 3. Method of Designing a Steam Turbine. 4. Com¬ 
plete Designs for DeLaval Steam Turbines; Method of Making 
Vanes; Shrouding. 5. The Theory of Multiple Stage Turbines. 
With detail drawings and tables. 85 pages, 74 illustrations. 

MODEL BOILER MAKING. A practical handbook on the de¬ 
signing, Making and Testing of small Steam Boilers. By E. L. 
Pearce. Contents of Chapters:—1. General principles of boiler 
design, materials, shape, proportions, strength, capacity, heating 
surface. 2. Stationery boilers. 3. Launch boilers. 4. Locomo¬ 
tive boilers. 5. Setting out plates, spacing tubes, etc. 6. Boiler 
fittings. 7. Fuel, lamps, fire-grates. 86 pages, 35 illustrations. 

GAS AND OIL ENGINES SIMPLY EXPLAINED. A practical 

handbook for Engine attendants. By W. C. Runciman. Contents 
of Chapters : Preface. 1. Introductory. 2. The component parts 
of an engine. 3. How a gas engine works. 4. Ignition devices, 
o Magneto i£ n ^ on ' 6. Governing. 7. Cams and valve settings. 
8 . Oil Engines. 88 pages, 51 illustrations. 





MODEL RAILWAYS. A handbook on the choice of model loco¬ 
motives and railway equipment, including designs for rail forma¬ 
tions, and model railway signaling. By W. J. Bassett-Lowke. 

72 pages, 80 illustrations, 8vo., paper. 25c. 

THE MODEL LOCOMOTIVE, its Design and Construction. A 
practical manual on the building and management of Miniature 
Railway Engines, by Henry Greenley. The book deals primarily 
with working model locomotives in all sizes, and for the most part 
for those built for the instruction and amusement of their owners. 
The subject is treated thoroughly and practically and profusely 
illustrated with details, diagrams and a number of large folding 
scale drawings. 276 pages, 9 in. x 5J in., cloth. $2,504 

THE WORLD’S LOCOMOTIVES. A digest of the latest loco¬ 
motive practice in the railway countries of the world. By Chas. 
S. Lake. Contents of Chapters: 1 . Introduction: Exigencies of 
Locomotive Design, Boiler Design and Construction. 2. Loco¬ 
motive Types; Cylinder and Wheel Arrangements. 3. British 
Locomotives: 4-4-0 Type Express Engines. 4. British Locomotives: 
4-4-2 Type Express Engines. 5. British Locomotives: Six Coupled, 
Single, and other Types of Express Engines. 6 . British Loco¬ 
motives: Tank Engines. 7. British Locomotives: Shunting, Con¬ 
tractors, Light Railway, and Crane Locomotives. 8 . British Loco 
motives: Goods Engines. 9. British Compound Locomotives. 10 
Colonial and Indian Locomotives. 11. Foreign Locomotives: Four- 
Coupled Express Engines. 12 . Foreign Locomotives: 4-6-0 and 
other Types. 13. Foreign Locomotives: Tank Engines. 14. For¬ 
eign Locomotives: Goods Engines. 15. American Passenger Loco¬ 
motives. 16. American Freight Locomotives. 380 pages, 376 
illustrations, 8 large folding scale plates. 4to., cloth. $4.00 net.§ 

MODERN BRITISH LOCOMOTIVES. By A. T. Taylor. 100 
diagrams to scale, principal dimensions and tables. Preface*. In 
compiling this volume, the author’s object has been to produce a 
book of reference which he hopes may fill a gap which exists in 
the ranks of locomotive publications. No pains have been spared 
in making the information given as trustworthy as possible, and 
the author takes this opportunity of thanking the different loco¬ 
motive engineers who have so courteously supplied the required 
information. The collection of diagrams represent the latest prac¬ 
tice on all the leading railways of Great Britain. 118 pages, oblong, 
8 vo., cloth. $2.00. 

LOCOMOTIVE CATECHISM. Containing 1600 questions and 
answers. This book commends itself to every engineer and fireman 
who are anxious for promotion. Written in plain language. 450 

pages, 223 illustrations, 24 folding plates, cloth. $2.00.$ 

LOCOMOTIVE SLIDE VALVE SETTING. A practical little treatise 
for the apprentice and all interested in locomotives. By C. E. 

Tulley. 31 pages, 29 illustrations, 16mo., limp cloth. 60c. 


THE GOMPOUND ENGINE 


BY 

W. J. TENNANT, A. M. I. Mech. E, 

Author of “ The Slide Valve Simply Explained .” 


“ The author has treated his subject in a thorough, practical 
manner, yet in plain language, avoiding all mathematics. The 
numerous diagrams, scale drawings and illustrations add very con¬ 
siderably to its value. It is a work that should be in the hands of 
every progressive young steam engineer”. 

Contents of Chapters. 

1. A General explanation of the Objects and Methods of Com¬ 
pounding. 

2. The Transfer of Steam from the High-Pressure to the Low- 
Pressure Cylinder; The Intermediate Receiver. 

3. The Size of the Low-Pressure Cylinder. 

4. Back-Pressure in the High-Pressure Cylinder becomes For¬ 
ward Pressure in the Low-Pressure Cylinder. 

5. The near Equivalent of an Experimental Compound Engine, 
and of Steam for Working it; Guage-Pressure and Absolute- 
Pressure ; Expansion-Diagram and Indicator Diagram. 

6 . Further Development of the Equivalent of a Sectional Com¬ 
pound Engine; its Mechanism. 

7. Determination of “Drop” in the Receiver, and of the 
Pressure resulting when volumes of Steam at Different Pres¬ 
sures are put into communication with each other. 

8 . Final development of the near Equivalent of an Experi¬ 
mental Compound Engine. 

9. Horse Power from Indicator-Diagram. 

10. Reasons why the Compound Engine is Economical; The 
Heat Trap Theory; Cylinder Ratios and Receiver Proportions. 

11 . Receiver Proportions ( continued ). 

12 . Addition of Theoretical Curve of Expansion to Indicator 
Diagram; Superheat due to Drop. 

13. Compounds, Triples and Quadruples; Steam Jackets. 

14. The Condenser and Air Pump. 

15. The Condenser and Air Pump, ( continued ). 

Appendix; With tables of dimensions of various types of Com¬ 
pound Engines. 102 pages. With 63 illustrations, detail draw¬ 
ings and folding plates, 12mo., cloth, $ 1,004 





Movable Valve Models, Diagrams and Charts. 


MEYER’S VALVE. A position diagram of cylinder with cut-off 
at l, £, $ and i stroke of piston. By W. H. Weightman. With 
movable valves. Printed on card. 25c. net. 

WORKING VALVE MODELS FOR MARINE ENGINEERS. A 

set of four cards: 1, Piston Valve with Steam Inside. 2, Piston 
Valve with Steam Outside. 3, Double-ported Slide Valve. 4, 
Common Slide Valve. Each card is in colors and has movable 
ports. Also full descriptive matter. In cloth case. 75c. net. 

WORKING MODELS OF ENGINE SLIDE VALVES. Comprising 
a complete-set of eight diagrams in colors, with movable ports: 
1 , Short D Slide Valve. 2, Single-acting Piston Valve (for Steam 
Hammer). 3, Meyer’s Variable Cut-off Valves. 4, Long D Slide 
Valve. 5, Short D Slide Valve (Balanced). 6, Marine Engine 
Piston Valve. 7, Double-ported Slide Valve. 8, Simple Trick 
Valve. With small booklet giving full instructions $1.25 net. 

WORKING MODEL “ X ” SERIES NO. 1 and 2. No. 1 com¬ 
plete simple steam engine single cylinder horizontal type fitted 
with a D slide valve, sectional view showing all movable and fixed 
parts, drawn to scale, printed in colors on heavy card, size 6x9$ in. 
$1.00 net, with book, $1.25 net. 

No. 2, complete single cylinder steam engine, horizontal girder 
type fitted with Meyer’s valve gear, sectional view showing all 
movable and fixed parts drawn to scale, printed in colors on 
heavy card, size 6x9$ in. $1.00 net, with book, $1.25 net. 

No. 1 and No. 2 together with book, $2.00 net. These are two 
exceptionally fine models, all moving parts so connected that there 
is practically no back lash, the relative positions of all moving 
parts are shown at every point in the stroke of the engine. 

CORLISS ENGINE CHART. A fine engraving showing relative 
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plates, etc., when cut-off takes place at $ stroke for each 15 de¬ 
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SLIDE VALVE CHART, showing position of the crank pin, 
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port opening, cut-off, release, full exhaust port opening and com¬ 
pression. With full directions. A blueprint, 14fxl0£, 

LOCOMOTIVE CHARTS. American type, a transparent edu¬ 
cational chart, with every part of the engine shown and numbered 
a good clear engraving size. 30x12 in. 25c. 

Atlantic type, a companion chart to above. 25c. 



WATER SOFTENING 

AND 

PURIFICATION 

THE SOFTENING AND CLARIFICATION 
OF HARD AND DIRTY WATERS. 

By HAROLD COLLET. 

Second Edition Revised. 


CONTENTS OF CHAPTERS. 

1 . Water Supplies—Hard Water; Hardness; Dirty Water; Town 
Waters. 

2 . Water for Steam Boilers—Quantity Evaporated; Deposit 
from Hard Water; Cost of Evaporation; Waste of Fuel Due to 
Scale; Acid Waters; Wear and Tear of Boiler Plates; Different 
Kinds of Deposit; Removal of Deposit; Blowing down Boilers; 
Boiler Compositions; Internal Scumming Apparatus; Surface Con¬ 
densers; Exhaust Steam; Oily Water; Explosions; Heating Hard 
Water; Cracking off Scale; Purifying Feed Water; Economizers; 
Feed-Water Heaters; Table of Fuel; Economy; Water-Tube Boilers. 

3. Water for Manufacturing and Technical Processes —Destruc¬ 
tion of Soap by Hard Water; Amount of Waste Soda; Lime; Dye¬ 
ing; Tanning; Paper-Making; Distilling. 

4 . Chemistry of Water Softening-—Softening Processes; Lime 
Process; Soda Process; Lime and Soda Process; Lime; Carbonate 
of Lime; Sulphate of Lime; Chloride of Calcium; Carbonate of 
Magnesia; Sulphate of Magnesia; Chloride of Magnesia; Iron; 
Corrosion; Sea Water; Greasy Water; Tidal Water. 

5. Reagents for Softening and Clarifying Water—Lime; Caustic 
Soda; Carbonate of Soda; Aluminate of Soda; Sulphate of Alu¬ 
mina; Alum; Sulphate of Iron; Solubilities of Different Substances 

6 . Clarification—Unassisted Settlement; Settling Vessels; As¬ 
sisted Settlement; Filtration; Filters of Different Kinds; Cloths. 

7. Drinking Water—Influence of Hardness; Sulphate Hardness; 
Magnesia; Softened Water; Waters Naturally Soft; Acid Waters; 
Lead in Water. 

8 . Testing Water—Directions for Taking Samples; Analysis; 
Volumetric Tests; Soap Test for Hardness; Burettes for Solutions; 
Dilution of Very Hard Waters; Acid Test for Alkalinity and 
Temporary Hardness; Strength of Acid; Testing Lime-Water; 
Soda Solutions; How to Make Test Solutions; Indicators; Useful 
Tables. Index. 177 pages, 6 illustrations, 12mo., cloth. $2.00*. 



Mechanical Draft. 

BY 

J. H. KINEALY, M. Am. Soc. M.E. 

Past President American Society Heating and Ventilating Engineers . 


PREFACE. 

In writing this book the author has assumed that those who 
will use it are familiar with boilers and engine plants, and he 
has had in mind the practicing engineer who is called upon to design 
power plants, and who must therefore decide when it is best to use 
some form of mechanical draft. The arrangement of the book is 
what the experience of the author in making calculations for mech¬ 
anical draft installations has shown him is probably the best. 
And he has tried to arrange the tables in such a way and in such 
a sequence that they may prove as useful to others as they have 
to him. 

CONTENTS OF CHAPTERS. 

1. General Discussion. Introduction; systems of medjanical 
draft; chimneys v. mechanical draft; mechanical draft and econ¬ 
omizers. 

2. Forced Draft. Systems; closed fire-room systen, dosed 
ashpit system; small fan required; usual pressure; forced draft and 
economisers; advantages; disadvantages. 

3. Induced Draft. Introduction; temperature of gases,; advan¬ 
tages; disadvantages. 

4. Fuel and Air. Weight of coal to be burned; evap.jration 
per lb. of coal; effect of rate of evaporation; weight of air required; 
volume of air and gases; volume of gases to handle; leakage; factor 
of safety. 

5. Draft. Relation to rate of combustion; resistance of grate; 
resistance due to economizer; draft required under different con¬ 
ditions. 

6. Economizers. Effect of adding; ordinary proportion and 

cost; increase of temperature of feed water. -> 

7. Fans. Type and proportions of fan used; relation between 
revolution of fan and draft; capacity of fan. 

8. Proportioning the Parts. Diameter of fan wheel required; 
speed at which the fan must run; power required to run the fan; 
size of engine required; steam used by fan engine; choosing the fan 
for forced draft, for induced draft without economizer, for induced 
draft with economizer; location of the fan; breeching and up-take; 
inlet chamber; discharge chimney; by-pass; water for bearings. 

Appendix. Tables. Index. 156 pages. 13 plates. 16mq. 

Cloth, $2.00. 





P^1 N color Mixing. 

A Practical Handbook 

For Painters, Decorators, and all Who Have to Mix Colors. 

Containing many samples of Oil and Water Paints of varieus 
colors, including the principal Graining Grounds , and upwards 
of 500 different Color Mixtures, with Hints on Color and 
Paint Mixing generally. Testing Colors, Receipts for 
Special Paints, &c ., &c. 

By ARTHUR SEYMOUR JENNINGS. 

Second Edition, Rewritten and Considerably Enlarged. 


Contents of Chapters. 

I. —Paint and Color Mixing. 

II. —Colors or Strainers. 

III. —Reds and How to Mix Them. 

IV. —Blues and How to Mix Them. 

V. —Yellows and How to Mix Them. 

VI. —Greens and How to Mix Them. 

VII. —Browns and How to Mix Them. 

VIII. —Greys and How to Mix them. 

IX. —Whites and How to Mix Them. 

X. —Black Japan in Color Mixing. 

XI. —Graining Grounds and Graining Colors. 

XII. —Water Paints, Painting and Varnishing over Water Paints, 
Distempers, &c. 

XIII. —Testing Colors, Purity' of Materials, Tone, Fineness of 
Grinding, Spreading Capacity, &c. 

XIV. —Notes on Color Harmony. 

XV. —Tables, Notes and Receipts, Care of Brushes, Putty Receipts, 
&c. Description of Colored Plates. Index. 


The eight plates contain 171 samples of Colors, Graining Grounds, Tints of 
Water Paints, and Non-Poisonous Distempers. 

This is the most Practical and 14p=to=Date Work on this Subject, is very 
clearly written, and will enable any man who studies it to make Bigger Wages. 

With 149 pages of descriptive matter, 8vo, cloth, price, $2.50 





SPONS’ ENCYCLOPEDIA 

OF THE 

Industrial Arts, Manufactures 

AND 

Commercial Products. 


EDKTED BY 

Q. G. ANDRE, F.G.S., Asso.=M. Inst. C.E. 

AND 

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Assisted by many prominent Manufacturers, Chemists and Scientists. 


This encyclopedia is written by practical men for practical men. 
Raw Materials form perhaps its most important feature and are 
dealt with in a way never before attempted. 

Manufacturers are discussed in detail from the manufacturing 
standpoint by manufacturers of acknowledged reputation. 

Special consideration is given to the utilization of waste, the pre¬ 
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. Technicalities are explained, and bibliographies (English, Ameri 
can, French, German, etc.), are appended to the principal articles. 

U Over 2,000 pages and nearly 2,000 illustrations. 

We are offering a Limited number of sets of a 

SPECIAL THREE VOLUME EDITION HANDSOMELY 
BOUND IN HALF-MOROCCO, CLOTH=GILT, 
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A NEW AMERICAN BOOK ON INDUSTRIAL ALCOHOL, 


A PRACTICAL HANDBOOK ON THE 

Distillation of Alcohol 

FROM FARM PRODUCTS AND 

DENATURING ALCOHOL. 

By F. B. WRIGHT. 


Including the Free Alcohol Law and its Amendment, the Govern¬ 
ment regulations therefore and a number of U. S. government 
authorized de-naturing formulas. 

In the preparation of this, the second edition, the author has 
followed his original plan of writing a plain practical handbook on 
the manufacture of alcohol and de-naturing for industrial pur¬ 
poses. This industry is bound to grow to enormous proportions 
as it has in Germany where over 100,000,000 gallons were manu¬ 
factured last year principally in small farm distilleries. This work 
is not intended as a scientific treatise but as a help to farmers 
and others wishing to go into this industry on a moderate scale. 

The original matter has been carefully revised. Some of the 
chapters rewritten and a very considerable amount of new informa¬ 
tion added. The total number of illustrations brought up to 60 
including a number of plates giving the layout of distilleries. 

Contents of Chapters. 

1 , Alcohol, its various forms and sources. 2, The preparation 
of mashes and Fermentation. 3, Simple Distilling Apparatus. .4, 
Modern Distilling Apparatus. 5, Rectification. 6, Malting. 7 
Alcohol from Potatoes. 8, Alcohol from Grain, Com, Wheat, Rice 
and other Cereals. 9, Alcohol from Beets. 10, Alcohol from Molasses 
and Sugar Cane. 11, Alcoholometry. 12, Distilling Plants. Their 
general arrangement and equipment. 13, De-natured Alcohol and 
U. S. Authorized De-naturing Formulae. 14, De-naturing Regu¬ 
lations in the United States. Index. 

281 pages, 60 illustrations and plates, 12m©., cloth, $1404 



Dubelle's Famous Formulas. 

KNOWN AS 

Nou Plus Ultra Soda Fountain Requisites of Modern Times 

By Q, H, DTJBELLE. 

A practical Receipt Book fO', Druggists, Chemists , Confectioners and Venders 

of Soda Water. 

S '(VOPSIS OF CONTENTS. 

Introduction.— Notes on natural fruit juices and improved me¬ 
thods for their preparation. Selecting the fruit. Washing and 
pressing the fruit. Treating the juice. Natural fruit syrups and 
mode of preparation. Simple or stock syrups. 

FORMULAS. 

Fruit Syrups.— Blackberry, black current, black raspberry, ca- 
tawba, cherry, concord grape, cranberry, lime, peach, pineapple, 
plum, quince, raspberry, red current, red orange, scuppernong grape, 
strawberry, wild grape. New Improved Artificial Fruit Syrups. — 
Apple, apricot, banana, bitter orange, blackberry, black current, 
cherry, citron, curacoa, grape, groseille, lemon, lime, mandarin, mul¬ 
berry, nectarine, peach, pear, pineapple, plum, quince, raspberry, 
red current, strawberry, sweet orange, lar.gerine, vanilla. Fancy 
Soda Fountain Syrups. —Ambrosia, capillaire, coca-kina, coca-van- 
llla, coca-vino, excelsior, imperial, kola-coca, kola-kina, kola-vanilla, 
kola-vino, nectar, noyean, orgeat, sherbet, syrup of roses, syrup of 
violets. Artificial Fruit Essences. —Apple, apricot, banana, berg¬ 
amot, blackberry, black cherry, black currant, blueberry, citron, 
cranberry, gooseberry, grape, lemon, lime fruit, melon, nectarine, 
orange, peach, pear, pineapple, plum, quince, raspberry, red currant, 
strawberry. Concentrated Fruit Phosphates. Acid solution of 
phosphate, strawberry, tangerine, wild cherry.— 29 different formulas. 
New Malt Phosphates— 36. Foreign and Domestic Wine Phos¬ 
phates—9. Cream-Fruit Lactarts — 28. Soluble Flavoring Ex¬ 
tracts and Essences—14. New Modern Punches— 18. Milk 
Punches— 17. Fruit Punches— 32. Fruit Meads— 1 8. New Fruit 
Champagnes— 17. New Egg Phosphates— 14. Fruit Juice Shakes 
— 24. Egg Phosphate Shakes. Hot Egg Phosphate Shakes. 
Wine Bitter Shakes— 12. Soluble Wine Bitters Extracts— 12. 
N kw Italian Lemonades— 18. Ice Cream Sodas— 39. Non-Poison- 
ous Colors. Foam Preparations. Miscellaneous Formulas— 26. 
Latest Novelties in Soda Fountain Mixtures— 7 . Tonics. —Beef, 
iron and cinchona; hypophosphite ; beef and coca ; beef, wine and 
iron ; beef, wine, iron and cinchona ; coca and calisaya. Lactarts. 
—Imperial tea ; mocha coffee ; nectar; Persian sherbert. Punches. 
Extracts. —Columbia root beer; ginger tonic ; soluble hop ale 
Lemonades. —French ; Vienna. Egg nogg. Hop ale. Hot tom. Malt 
wine. Sherry cobbler. Saratoga milk shake. Pancretin and wine. 
Kola-coco cordial/ Iron malt phosphate. Pepsin, wine andiron, etc 

157 Pages, Nearly 500 Formulas. 12mo, Clotk, $1.00 



MODEL AEROPLANES. 


MODEL FLYING MACHINES, THEIR DESIGN AND CO 
ST RUCTION. By W. G. Aston. Contents of chapters: — 
General principles and their application. 2. Power. 3. Suppo: 
ing surfaces. 4. Screws, and how to make them. 5. Tails ai 
elevators. 6. Fins. 7. Designs. With a number of examples 
monoplane, bi-plane, tandem bi-plane and tri-plane models. 
Dirigibles. 9. Helicopters. 10. Ornithopters. 11. Winding a 
paratus. 12. Compressed air motor. A lirst-rate book for Mod 
Makers, 125 pages, 95 illustrations, 12mo. boards, postpaid, for 51 
MODEL GLIDERS, BIRDS, BUTTERFLIES AND AER 
PLANES. How to Make and Fly Them. A booklet with oi 
large sheet containing twelve butterflies and two birds in colo 
and material for making a small card-board Model Aeropla: 
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MODEL AEROPLANES, HOW TO BUILD AND FLY THEI 
By E. W. Twining. Consisting of one booklet and five lar 
scaled drawings for three Twining Models, two of them bei: 
of the Bi-plane Glider type. Complete in folder, postpaid, for 51 
TWINING'S MODEL NO. 2. A complete set of the materif 
in the rough, including the rubber of a Bi-plane Model withe 
th drawings, postpaid, for 65c. 

TWINING’S MODEL NO. 3. A complete set of materh 
in the rough with rubber for the construction of this handsoi 
Model Bi-plane without the drawings, postpaid, for $1.15. 

THE AEROPLANE PORTFOLIO. By D. Ross Kennedy. C< 
taining nine sheets of scale drawings of the following celebrat 
Aeroplanes: Bi-plane type—Wright, Farman, Voisin, Cody, H 
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The complete set in folder, postpaid, for 55c. 

THE PERCY PIERCE FLYER. A large scale drawing of t 
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with 8-page descriptive booklet of particulars postpaid, 15c. 

PERCY PIERCE DRAWING, with booklet and complete set 
materials in the rough from which any one can make an ex 
duplicate of this dandy Model complete, postpaid, for $1.15. 

A THREE-FOOT MODEL AEROPLANE. Bleriot Type. 

G. E. Alexander. A large scale drawing with measurements z 
descriptive matter showing the construction of a splendid Mo 
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LIBRARY OF CONGRESS 


0 033 266 304,5 


The Latest and Best Book 


on 


The Theory and Practice 
of 

Model Aeroplaning 

By V. E. JOHNSON . M.A. 

The object of this book is to give in plain 
language the general practice and principles of 
Model Aeroplaning. Model propellors and motors 
have been carefully dealt with, and much valu¬ 
able data iucluded from the authors own experi¬ 
ments. 

CONTENTS OF CHAPTERS. 

Glossary of Terms used in Model Aeroplaning. 
Introduction. 

1. The Question of Weight. 

2 . The Question of Resistance. 

3. The Question of Balance. 

4. Motive Power. Rubber Motors and other 

forms of Motors. 

5. Propellors or Screws. 

6 . The Question of Sustention. The center of 

pressure. 

7. Materials for Aeroplane construction. 

8 . Hints on the building of Model Aeroplanes. 

9. The Steering of the model. 

10 . The launching of the model. 

11. Helicopter Models. 

12 . Experimental records. 

13. Model Flying competitions. 

14* Useful notes, tables, formulae, etc., etc., 

163 pages, 82 illustrations, 12mo Cloth, $1.30. 


















